Coolant fan override switch

[David Brady]

Got it. Thanks everyone, I really appreciate your help.
I got some testing to do, but it's going to have to wait a
few days.

David B
'02 LXi, Smokey
NC

Gregory OConnor wrote:
> David, Bypass and override are two independent features. I believe
> bypass is a safety feature for a clogged hydro oil filter. Bypass is
> not triggered by the override dash switch
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, David Brady
> wrote:
>
>> Hi Rich,
>>
>> Thanks for the help. When I return to the bus I'll try your test.
>> I guess if the fan speed increases, then the problem is between
>> the dash switch and the "bypass valve". Alas, no wiring schematics..
>> I'll let you know what happens.
>>
>>
>> David B
>> '02 LXi, Smokey
>> NC
>>
>> g_man1146 wrote:
>>
>>> Hi David,
>>>
>>> AS others have stated, a fan over-ride failure should fault to
>>>
> high
>
>>> speed. If you are not getting high fan speed with the air
>>>
> conditioner
>
>>> on or with the switch set to "over-ride" locate (assuming Detroit
>>>
> S60)
>
>>> a connector plug at the rear of the engine compartment (closest
>>>
> to rear
>
>>> bumper) on the fan side. You should see a hydraulic hose from the
>>>
> fan
>
>>> motor to this block (bypass valve) and wires coming from it. If
>>>
> you
>
>>> disconnect the connector plug on these wires, the fan should come
>>>
> up to
>
>>> full RPM. (ROAR) If it increases but not fully, the problem may
>>>
> lie
>
>>> with the hydraulic pump which is attached to the PTO on the curb
>>>
> side
>
>>> of the Allison or with the hydraulic bypass valve. BB makes
>>>
> changes all
>
>>> the time and my coach (3 years older) may not be set up the same.
>>>
> If
>
>>> you are not overheating on long hills everything may be normal. I
>>> experienced an overheating situation only in extreme situations
>>>
> and
>
>>> determined the problem to be a faulty hydraulic pump supplied as
>>>
> part
>
>>> of the PTO recall from BB. The pump did not have sufficient
>>>
> capacity to
>
>>> run the fan at full speed. They supplied a new pump and labor to
>>> install. The fan motor is actually rated at about 40 HP at full
>>> capacity. No wonder it is designed to cut back when not needed!
>>>
>>> Rich D. '99LXi43' CT
>>>
>>> --- In WanderlodgeForum@yahoogroups.com, David Brady
>>>
> wrote:
>
>>>
>>>
>>>> Folks,
>>>>
>>>> On my '02 LXi, with the engine at idle, the fan seems to rotate
>>>> at 400 rpm or so (give or take, lol), when I enable the override
>>>> switch there doesn't seem to be any change in fan speed. Should
>>>> there be? or are there other parameters at work hear; i.e.,
>>>>
> engine
>
>>>> temp, etc. What are the common failure modes of the fan override?
>>>>
>>>> Thanks,
>>>> David Brady
>>>> '02 LXi, Smokey
>>>> NC
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>



[Non-text portions of this message have been removed]

[Leroy Eckert]

Thanks Ron:
When I started having creeping heat I could not figure it out. I changed the
Alarmstat and it stopped. Apparantly, the sensor did not fail totally but was
intermittant, causing the fan to act weird. After I changed it to the factory
value, 195 degrees, I did not like the average water temperature. So I ordered
a 190 degree and I like the results of it much better.
The problem is you cannot test the sensor while sitting still, and you cannot
hear the fan while driving. You can only see the result on the temperature guage
with the override off and the a/c off. It makes it difficult to troubleshoot.

Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville, FL





----- Original Message -----
From: ronmarabito2002
To: WanderlodgeForum@yahoogroups.com
Sent: Monday, February 19, 2007 7:46 PM
Subject: [WanderlodgeForum] Re: Coolant fan override switch


I have not had a alarmstat failure on my 92, but I did on my 83PT40.
It definitely failed into high speed fan mode.

R.E. (Ron) Marabito, Dallas, TX 92WB40

--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
>
>
> This is exactly how my system works. I would think yours is similar.
> 1.With the fan override off and chassis a/c off the fan will spool
between approx 400x600 RPM. This continues until the temperature
reaches 195 degrees, (190 degrees now in my coach) then an alarmstat
turns the fan to high speed approx. 1800 RPM. The alarmstat operates
in an 8 to10 degree range, therefore cycling the fan from idle to
high mode over and over again, hence the cycling you may see on the
engine water temperature gauge. ( you will not see the cycling with
the chassis a/c on.) you may not see cycling in this configuration in
hot temperatures or while climbing hills.
>
> 2. Fan override off, and chassis a/c on: When the chassis a/c
switch is turned on( either pilot or co-pilot) the fan goes into high
mode, stays in high mode until the a/c switch is turned off. This
takes the fan override and the alarmstat out of the system, and
provides additional continuous cooling air for the condenser. My
condenser covers the top half of the radiator. Earlier models a/c
condenser are on the roof, cooled by electric fans.
>
> 3. Fan override on, chassis a/c off. Operates the same as item 2.
except the fan override switch has now taken the Alarmstat out of the
system. Using this switch in winter in my coach holds the engine
water temperature at engine thermostat value approx. 170-175. I
expect to see continuous 190 or less in summer in this configuration.
>
> 4. When my alarmstat failed/or became intermittent I experienced
creeping heat. I'm told that alarmstat failure is suppose to default
to fan high mode. I have not verified that.
>
> 4. So you see, Bluebirds engineers forced our coaches to run on the
high side of the DD specified range ( 170-210max, alarmed at 215
degrees: Ref: 13.12 DD Service Manual Pg. 13-48) by specifying the
195 degree alarmstat. Presumably, the thinking is that high fan RPM
robs power so the higher you run the temperature the less fan
activity. Unfortunately, that simply isn't the case because once the
195 degree temperature is attained the fan cycles continuously anyway.
It does the same thing in my bus using a 190 degree alarmstat ,
however, the benefit of the lower water temperature is lower engine
oil, tranny and retarder temperatures.
>
> When it gets hot, I intend to use my VMSpc to evaluate the
temperature differences resulting from my alarmstat value change from
195 degree to 190 degree. I fully expect to see a 6-8 percent
reduction in drivetrain component temperatures.
>
> The foregoing post has been documented with temperature values,
estimated outside air temps and road conditions while driving my 1990
WB-40 over the past 5 months.
>
> Leroy Eckert
> 1990 WB-40
> "Smoke N Mirrors"
>
>
>
>
>
>
> ----- Original Message -----
> From: David Brady
> To: WanderlodgeForum@yahoogroups.com
> Sent: Sunday, February 18, 2007 10:36 PM
> Subject: [WanderlodgeForum] Coolant fan override switch
>
>
> Folks,
>
> On my '02 LXi, with the engine at idle, the fan seems to rotate
> at 400 rpm or so (give or take, lol), when I enable the override
> switch there doesn't seem to be any change in fan speed. Should
> there be? or are there other parameters at work hear; i.e., engine
> temp, etc. What are the common failure modes of the fan override?
>
> Thanks,
> David Brady
> '02 LXi, Smokey
> NC
>
>
>
>
> [Non-text portions of this message have been removed]
>





[Non-text portions of this message have been removed]

[Leroy Eckert]

That was to Greg, but I think we are all speaking of the same thing, just a
different component in the system with a bypass. The fan control valve has a
bypass as does the Parker filter. The override sends a message so to speak to
the valve to stop the bypass and get into high mode. So does the chassis a/c on
switch. If the valve is bad, the fan will not spool up.

Leroy Eckert
1990 WB-40"smoke N Mirrors"
Niceville, FL





----- Original Message -----
From: g_man1146
To: WanderlodgeForum@yahoogroups.com
Sent: Monday, February 19, 2007 9:08 PM
Subject: [WanderlodgeForum] Re: Coolant fan override switch


Gregory,

On the later model Series 60's the fan bypass valve diverts
hydraulic oil around the fan motor to allow the fan to run at a
lower speed by sending the oil back without going through the
fan "motor". If the bypass valve fails, you get full RPM of the fan
as all of the oil is directed to the fan motor. This has nothing to
do with a filter bypass. The bypass valve can also be tested by
plugging the return line that goes to the bypass valve thus forcing
all oil through the fan motor.

Rich D. '99LXi43' CT

--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
> Yes.
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Nicevile, FL
>
>
> ----- Original Message -----
> From: Gregory OConnor
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 8:02 PM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> David, Bypass and override are two independent features. I
believe
> bypass is a safety feature for a clogged hydro oil filter.
Bypass is
> not triggered by the override dash switch
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, David Brady
> wrote:
> >
> > Hi Rich,
> >
> > Thanks for the help. When I return to the bus I'll try your
test.
> > I guess if the fan speed increases, then the problem is between
> > the dash switch and the "bypass valve". Alas, no wiring
schematics..
> > I'll let you know what happens.
> >
> >
> > David B
> > '02 LXi, Smokey
> > NC
> >
> > g_man1146 wrote:
> > > Hi David,
> > >
> > > AS others have stated, a fan over-ride failure should fault
to
> high
> > > speed. If you are not getting high fan speed with the air
> conditioner
> > > on or with the switch set to "over-ride" locate (assuming
Detroit
> S60)
> > > a connector plug at the rear of the engine compartment
(closest
> to rear
> > > bumper) on the fan side. You should see a hydraulic hose
from the
> fan
> > > motor to this block (bypass valve) and wires coming from it.
If
> you
> > > disconnect the connector plug on these wires, the fan should
come
> up to
> > > full RPM. (ROAR) If it increases but not fully, the problem
may
> lie
> > > with the hydraulic pump which is attached to the PTO on the
curb
> side
> > > of the Allison or with the hydraulic bypass valve. BB makes
> changes all
> > > the time and my coach (3 years older) may not be set up the
same.
> If
> > > you are not overheating on long hills everything may be
normal. I
> > > experienced an overheating situation only in extreme
situations
> and
> > > determined the problem to be a faulty hydraulic pump
supplied as
> part
> > > of the PTO recall from BB. The pump did not have sufficient
> capacity to
> > > run the fan at full speed. They supplied a new pump and
labor to
> > > install. The fan motor is actually rated at about 40 HP at
full
> > > capacity. No wonder it is designed to cut back when not
needed!
> > >
> > > Rich D. '99LXi43' CT
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, David Brady

> wrote:
> > >
> > >> Folks,
> > >>
> > >> On my '02 LXi, with the engine at idle, the fan seems to
rotate
> > >> at 400 rpm or so (give or take, lol), when I enable the
override
> > >> switch there doesn't seem to be any change in fan speed.
Should
> > >> there be? or are there other parameters at work hear; i.e.,
> engine
> > >> temp, etc. What are the common failure modes of the fan
override?
> > >>
> > >> Thanks,
> > >> David Brady
> > >> '02 LXi, Smokey
> > >> NC
> > >>
> > >>
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>





[Non-text portions of this message have been removed]

[Leroy Eckert]

Rich: I have a question on the bypass valve if you know. I do not have a
drawing of the valve.

As I understand the system, the fan is normally in idle(bypass) mode until one
of three things happen. The alarmstat activates high mode based on water
temperature, the fan override(manually by humans or grandkids) activates high
mode or the chassis a/c on switch activates high mode.
Does the fan bypass valve default to fan high mode? . That would make sense
otherwise the system would overheat with valve or electrical failure. If so,
one could conclude that the piston in the valve is actuated by continuous power
in the bypass position and the fan override, a/c switch and alarmstat cuts power
off to it and it is spring loaded to full fan mode.

If you know. Thanks. Trying to learn more here.


Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville,FL






----- Original Message -----
From: Leroy Eckert
To: WanderlodgeForum@yahoogroups.com
Sent: Monday, February 19, 2007 9:35 PM
Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch


That was to Greg, but I think we are all speaking of the same thing, just a
different component in the system with a bypass. The fan control valve has a
bypass as does the Parker filter. The override sends a message so to speak to
the valve to stop the bypass and get into high mode. So does the chassis a/c on
switch. If the valve is bad, the fan will not spool up.

Leroy Eckert
1990 WB-40"smoke N Mirrors"
Niceville, FL

----- Original Message -----
From: g_man1146
To: WanderlodgeForum@yahoogroups.com
Sent: Monday, February 19, 2007 9:08 PM
Subject: [WanderlodgeForum] Re: Coolant fan override switch

Gregory,

On the later model Series 60's the fan bypass valve diverts
hydraulic oil around the fan motor to allow the fan to run at a
lower speed by sending the oil back without going through the
fan "motor". If the bypass valve fails, you get full RPM of the fan
as all of the oil is directed to the fan motor. This has nothing to
do with a filter bypass. The bypass valve can also be tested by
plugging the return line that goes to the bypass valve thus forcing
all oil through the fan motor.

Rich D. '99LXi43' CT

--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
> Yes.
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Nicevile, FL
>
>
> ----- Original Message -----
> From: Gregory OConnor
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 8:02 PM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> David, Bypass and override are two independent features. I
believe
> bypass is a safety feature for a clogged hydro oil filter.
Bypass is
> not triggered by the override dash switch
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, David Brady
> wrote:
> >
> > Hi Rich,
> >
> > Thanks for the help. When I return to the bus I'll try your
test.
> > I guess if the fan speed increases, then the problem is between
> > the dash switch and the "bypass valve". Alas, no wiring
schematics..
> > I'll let you know what happens.
> >
> >
> > David B
> > '02 LXi, Smokey
> > NC
> >
> > g_man1146 wrote:
> > > Hi David,
> > >
> > > AS others have stated, a fan over-ride failure should fault
to
> high
> > > speed. If you are not getting high fan speed with the air
> conditioner
> > > on or with the switch set to "over-ride" locate (assuming
Detroit
> S60)
> > > a connector plug at the rear of the engine compartment
(closest
> to rear
> > > bumper) on the fan side. You should see a hydraulic hose
from the
> fan
> > > motor to this block (bypass valve) and wires coming from it.
If
> you
> > > disconnect the connector plug on these wires, the fan should
come
> up to
> > > full RPM. (ROAR) If it increases but not fully, the problem
may
> lie
> > > with the hydraulic pump which is attached to the PTO on the
curb
> side
> > > of the Allison or with the hydraulic bypass valve. BB makes
> changes all
> > > the time and my coach (3 years older) may not be set up the
same.
> If
> > > you are not overheating on long hills everything may be
normal. I
> > > experienced an overheating situation only in extreme
situations
> and
> > > determined the problem to be a faulty hydraulic pump
supplied as
> part
> > > of the PTO recall from BB. The pump did not have sufficient
> capacity to
> > > run the fan at full speed. They supplied a new pump and
labor to
> > > install. The fan motor is actually rated at about 40 HP at
full
> > > capacity. No wonder it is designed to cut back when not
needed!
> > >
> > > Rich D. '99LXi43' CT
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, David Brady

> wrote:
> > >
> > >> Folks,
> > >>
> > >> On my '02 LXi, with the engine at idle, the fan seems to
rotate
> > >> at 400 rpm or so (give or take, lol), when I enable the
override
> > >> switch there doesn't seem to be any change in fan speed.
Should
> > >> there be? or are there other parameters at work hear; i.e.,
> engine
> > >> temp, etc. What are the common failure modes of the fan
override?
> > >>
> > >> Thanks,
> > >> David Brady
> > >> '02 LXi, Smokey
> > >> NC
> > >>
> > >>
> > >
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

[Gregory OConnor]

Ok,Is the fan pump on the S60 also the Powersteering pump. Is there a
filter by pass?
GregoryO'Connor
94ptRomolandCa

--- In WanderlodgeForum@yahoogroups.com, "g_man1146"
wrote:
>
> Gregory,
>
> On the later model Series 60's the fan bypass valve diverts
> hydraulic oil around the fan motor to allow the fan to run at a
> lower speed by sending the oil back without going through the
> fan "motor". If the bypass valve fails, you get full RPM of the fan
> as all of the oil is directed to the fan motor. This has nothing to
> do with a filter bypass. The bypass valve can also be tested by
> plugging the return line that goes to the bypass valve thus forcing
> all oil through the fan motor.
>
> Rich D. '99LXi43' CT
>
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Yes.
> >
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Nicevile, FL
> >
> >
> > ----- Original Message -----
> > From: Gregory OConnor
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 8:02 PM
> > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> >
> >
> > David, Bypass and override are two independent features. I
> believe
> > bypass is a safety feature for a clogged hydro oil filter.
> Bypass is
> > not triggered by the override dash switch
> > GregoryO'Connor
> > 94ptRomolandCa
> >
> > --- In WanderlodgeForum@yahoogroups.com, David Brady
> > wrote:
> > >
> > > Hi Rich,
> > >
> > > Thanks for the help. When I return to the bus I'll try your
> test.
> > > I guess if the fan speed increases, then the problem is
between
> > > the dash switch and the "bypass valve". Alas, no wiring
> schematics..
> > > I'll let you know what happens.
> > >
> > >
> > > David B
> > > '02 LXi, Smokey
> > > NC
> > >
> > > g_man1146 wrote:
> > > > Hi David,
> > > >
> > > > AS others have stated, a fan over-ride failure should fault
> to
> > high
> > > > speed. If you are not getting high fan speed with the air
> > conditioner
> > > > on or with the switch set to "over-ride" locate (assuming
> Detroit
> > S60)
> > > > a connector plug at the rear of the engine compartment
> (closest
> > to rear
> > > > bumper) on the fan side. You should see a hydraulic hose
> from the
> > fan
> > > > motor to this block (bypass valve) and wires coming from
it.
> If
> > you
> > > > disconnect the connector plug on these wires, the fan
should
> come
> > up to
> > > > full RPM. (ROAR) If it increases but not fully, the problem
> may
> > lie
> > > > with the hydraulic pump which is attached to the PTO on the
> curb
> > side
> > > > of the Allison or with the hydraulic bypass valve. BB makes
> > changes all
> > > > the time and my coach (3 years older) may not be set up the
> same.
> > If
> > > > you are not overheating on long hills everything may be
> normal. I
> > > > experienced an overheating situation only in extreme
> situations
> > and
> > > > determined the problem to be a faulty hydraulic pump
> supplied as
> > part
> > > > of the PTO recall from BB. The pump did not have sufficient
> > capacity to
> > > > run the fan at full speed. They supplied a new pump and
> labor to
> > > > install. The fan motor is actually rated at about 40 HP at
> full
> > > > capacity. No wonder it is designed to cut back when not
> needed!
> > > >
> > > > Rich D. '99LXi43' CT
> > > >
> > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
>
> > wrote:
> > > >
> > > >> Folks,
> > > >>
> > > >> On my '02 LXi, with the engine at idle, the fan seems to
> rotate
> > > >> at 400 rpm or so (give or take, lol), when I enable the
> override
> > > >> switch there doesn't seem to be any change in fan speed.
> Should
> > > >> there be? or are there other parameters at work hear;
i.e.,
> > engine
> > > >> temp, etc. What are the common failure modes of the fan
> override?
> > > >>
> > > >> Thanks,
> > > >> David Brady
> > > >> '02 LXi, Smokey
> > > >> NC
> > > >>
> > > >>
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>

[g_man1146]

The pump is attached to a PTO on the curb side of the transmission
and the only lines I see go to the fan. No filter bypass on mine.
This setup is quite different than that on my previous '90 PT40 8V92.

Rich D. '99LXi43' CT


--- In WanderlodgeForum@yahoogroups.com, "Gregory OConnor"
wrote:
>
> Ok,Is the fan pump on the S60 also the Powersteering pump. Is there
a
> filter by pass?
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, "g_man1146"
> wrote:
> >
> > Gregory,
> >
> > On the later model Series 60's the fan bypass valve diverts
> > hydraulic oil around the fan motor to allow the fan to run at a
> > lower speed by sending the oil back without going through the
> > fan "motor". If the bypass valve fails, you get full RPM of the
fan
> > as all of the oil is directed to the fan motor. This has nothing
to
> > do with a filter bypass. The bypass valve can also be tested by
> > plugging the return line that goes to the bypass valve thus
forcing
> > all oil through the fan motor.
> >
> > Rich D. '99LXi43' CT
> >
> >
> > --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> > wrote:
> > >
> > > Yes.
> > >
> > > Leroy Eckert
> > > 1990 WB-40"Smoke N Mirrors"
> > > Nicevile, FL
> > >
> > >
> > > ----- Original Message -----
> > > From: Gregory OConnor
> > > To: WanderlodgeForum@yahoogroups.com
> > > Sent: Monday, February 19, 2007 8:02 PM
> > > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> > >
> > >
> > > David, Bypass and override are two independent features. I
> > believe
> > > bypass is a safety feature for a clogged hydro oil filter.
> > Bypass is
> > > not triggered by the override dash switch
> > > GregoryO'Connor
> > > 94ptRomolandCa
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, David Brady

> > > wrote:
> > > >
> > > > Hi Rich,
> > > >
> > > > Thanks for the help. When I return to the bus I'll try your
> > test.
> > > > I guess if the fan speed increases, then the problem is
> between
> > > > the dash switch and the "bypass valve". Alas, no wiring
> > schematics..
> > > > I'll let you know what happens.
> > > >
> > > >
> > > > David B
> > > > '02 LXi, Smokey
> > > > NC
> > > >
> > > > g_man1146 wrote:
> > > > > Hi David,
> > > > >
> > > > > AS others have stated, a fan over-ride failure should
fault
> > to
> > > high
> > > > > speed. If you are not getting high fan speed with the air
> > > conditioner
> > > > > on or with the switch set to "over-ride" locate (assuming
> > Detroit
> > > S60)
> > > > > a connector plug at the rear of the engine compartment
> > (closest
> > > to rear
> > > > > bumper) on the fan side. You should see a hydraulic hose
> > from the
> > > fan
> > > > > motor to this block (bypass valve) and wires coming from
> it.
> > If
> > > you
> > > > > disconnect the connector plug on these wires, the fan
> should
> > come
> > > up to
> > > > > full RPM. (ROAR) If it increases but not fully, the
problem
> > may
> > > lie
> > > > > with the hydraulic pump which is attached to the PTO on
the
> > curb
> > > side
> > > > > of the Allison or with the hydraulic bypass valve. BB
makes
> > > changes all
> > > > > the time and my coach (3 years older) may not be set up
the
> > same.
> > > If
> > > > > you are not overheating on long hills everything may be
> > normal. I
> > > > > experienced an overheating situation only in extreme
> > situations
> > > and
> > > > > determined the problem to be a faulty hydraulic pump
> > supplied as
> > > part
> > > > > of the PTO recall from BB. The pump did not have
sufficient
> > > capacity to
> > > > > run the fan at full speed. They supplied a new pump and
> > labor to
> > > > > install. The fan motor is actually rated at about 40 HP
at
> > full
> > > > > capacity. No wonder it is designed to cut back when not
> > needed!
> > > > >
> > > > > Rich D. '99LXi43' CT
> > > > >
> > > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
> >
> > > wrote:
> > > > >
> > > > >> Folks,
> > > > >>
> > > > >> On my '02 LXi, with the engine at idle, the fan seems to
> > rotate
> > > > >> at 400 rpm or so (give or take, lol), when I enable the
> > override
> > > > >> switch there doesn't seem to be any change in fan speed.
> > Should
> > > > >> there be? or are there other parameters at work hear;
> i.e.,
> > > engine
> > > > >> temp, etc. What are the common failure modes of the fan
> > override?
> > > > >>
> > > > >> Thanks,
> > > > >> David Brady
> > > > >> '02 LXi, Smokey
> > > > >> NC
> > > > >>
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
>

[g_man1146]

Leroy,
You are correct; the fan bypass defaults to closed, thereby forcing
all of the pump output through the fan motor. Cool temperatures, air
conditioner "ON" or "Fan Override" switch "ON" all hold the bypass
valve open allowing oil to flow around the fan motor. When I was
attempting to diagnose what turned out to be a defective pump, BB
sent me a diagram and test procedure to follow. They said the LXi
shared the same system as the "LTC" commercial coach.

Rich D. '99LXi43' CT


--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
> Rich: I have a question on the bypass valve if you know. I do not
have a drawing of the valve.
>
> As I understand the system, the fan is normally in idle(bypass)
mode until one of three things happen. The alarmstat activates high
mode based on water temperature, the fan override(manually by humans
or grandkids) activates high mode or the chassis a/c on switch
activates high mode.
> Does the fan bypass valve default to fan high mode? . That would
make sense otherwise the system would overheat with valve or
electrical failure. If so, one could conclude that the piston in the
valve is actuated by continuous power in the bypass position and the
fan override, a/c switch and alarmstat cuts power off to it and it is
spring loaded to full fan mode.
>
> If you know. Thanks. Trying to learn more here.
>
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Niceville,FL
>
>
>
>
>
>
> ----- Original Message -----
> From: Leroy Eckert
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 9:35 PM
> Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> That was to Greg, but I think we are all speaking of the same
thing, just a different component in the system with a bypass. The
fan control valve has a bypass as does the Parker filter. The
override sends a message so to speak to the valve to stop the bypass
and get into high mode. So does the chassis a/c on switch. If the
valve is bad, the fan will not spool up.
>
> Leroy Eckert
> 1990 WB-40"smoke N Mirrors"
> Niceville, FL
>
> ----- Original Message -----
> From: g_man1146
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 9:08 PM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
> Gregory,
>
> On the later model Series 60's the fan bypass valve diverts
> hydraulic oil around the fan motor to allow the fan to run at a
> lower speed by sending the oil back without going through the
> fan "motor". If the bypass valve fails, you get full RPM of the
fan
> as all of the oil is directed to the fan motor. This has nothing
to
> do with a filter bypass. The bypass valve can also be tested by
> plugging the return line that goes to the bypass valve thus
forcing
> all oil through the fan motor.
>
> Rich D. '99LXi43' CT
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Yes.
> >
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Nicevile, FL
> >
> >
> > ----- Original Message -----
> > From: Gregory OConnor
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 8:02 PM
> > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> >
> >
> > David, Bypass and override are two independent features. I
> believe
> > bypass is a safety feature for a clogged hydro oil filter.
> Bypass is
> > not triggered by the override dash switch
> > GregoryO'Connor
> > 94ptRomolandCa
> >
> > --- In WanderlodgeForum@yahoogroups.com, David Brady
> > wrote:
> > >
> > > Hi Rich,
> > >
> > > Thanks for the help. When I return to the bus I'll try your
> test.
> > > I guess if the fan speed increases, then the problem is
between
> > > the dash switch and the "bypass valve". Alas, no wiring
> schematics..
> > > I'll let you know what happens.
> > >
> > >
> > > David B
> > > '02 LXi, Smokey
> > > NC
> > >
> > > g_man1146 wrote:
> > > > Hi David,
> > > >
> > > > AS others have stated, a fan over-ride failure should fault
> to
> > high
> > > > speed. If you are not getting high fan speed with the air
> > conditioner
> > > > on or with the switch set to "over-ride" locate (assuming
> Detroit
> > S60)
> > > > a connector plug at the rear of the engine compartment
> (closest
> > to rear
> > > > bumper) on the fan side. You should see a hydraulic hose
> from the
> > fan
> > > > motor to this block (bypass valve) and wires coming from
it.
> If
> > you
> > > > disconnect the connector plug on these wires, the fan
should
> come
> > up to
> > > > full RPM. (ROAR) If it increases but not fully, the problem
> may
> > lie
> > > > with the hydraulic pump which is attached to the PTO on the
> curb
> > side
> > > > of the Allison or with the hydraulic bypass valve. BB makes
> > changes all
> > > > the time and my coach (3 years older) may not be set up the
> same.
> > If
> > > > you are not overheating on long hills everything may be
> normal. I
> > > > experienced an overheating situation only in extreme
> situations
> > and
> > > > determined the problem to be a faulty hydraulic pump
> supplied as
> > part
> > > > of the PTO recall from BB. The pump did not have sufficient
> > capacity to
> > > > run the fan at full speed. They supplied a new pump and
> labor to
> > > > install. The fan motor is actually rated at about 40 HP at
> full
> > > > capacity. No wonder it is designed to cut back when not
> needed!
> > > >
> > > > Rich D. '99LXi43' CT
> > > >
> > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
>
> > wrote:
> > > >
> > > >> Folks,
> > > >>
> > > >> On my '02 LXi, with the engine at idle, the fan seems to
> rotate
> > > >> at 400 rpm or so (give or take, lol), when I enable the
> override
> > > >> switch there doesn't seem to be any change in fan speed.
> Should
> > > >> there be? or are there other parameters at work hear;
i.e.,
> > engine
> > > >> temp, etc. What are the common failure modes of the fan
> override?
> > > >>
> > > >> Thanks,
> > > >> David Brady
> > > >> '02 LXi, Smokey
> > > >> NC
> > > >>
> > > >>
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

[Leroy Eckert]

Ok, thanks. Now all I have to figure out is how any one of the three components
disables the other two when in high mode. Somehow, the a/c and override switch
must be tied to the Alarmstat NC sensor . I just haven't figured that one out. I
want to make an electrical drawing of my system. If I figure it out, I'll post
it.

Thanks,

Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville, FL



----- Original Message -----
From: g_man1146
To: WanderlodgeForum@yahoogroups.com
Sent: Tuesday, February 20, 2007 9:11 AM
Subject: [WanderlodgeForum] Re: Coolant fan override switch


Leroy,
You are correct; the fan bypass defaults to closed, thereby forcing
all of the pump output through the fan motor. Cool temperatures, air
conditioner "ON" or "Fan Override" switch "ON" all hold the bypass
valve open allowing oil to flow around the fan motor. When I was
attempting to diagnose what turned out to be a defective pump, BB
sent me a diagram and test procedure to follow. They said the LXi
shared the same system as the "LTC" commercial coach.

Rich D. '99LXi43' CT

--- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
wrote:
>
> Rich: I have a question on the bypass valve if you know. I do not
have a drawing of the valve.
>
> As I understand the system, the fan is normally in idle(bypass)
mode until one of three things happen. The alarmstat activates high
mode based on water temperature, the fan override(manually by humans
or grandkids) activates high mode or the chassis a/c on switch
activates high mode.
> Does the fan bypass valve default to fan high mode? . That would
make sense otherwise the system would overheat with valve or
electrical failure. If so, one could conclude that the piston in the
valve is actuated by continuous power in the bypass position and the
fan override, a/c switch and alarmstat cuts power off to it and it is
spring loaded to full fan mode.
>
> If you know. Thanks. Trying to learn more here.
>
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Niceville,FL
>
>
>
>
>
>
> ----- Original Message -----
> From: Leroy Eckert
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 9:35 PM
> Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> That was to Greg, but I think we are all speaking of the same
thing, just a different component in the system with a bypass. The
fan control valve has a bypass as does the Parker filter. The
override sends a message so to speak to the valve to stop the bypass
and get into high mode. So does the chassis a/c on switch. If the
valve is bad, the fan will not spool up.
>
> Leroy Eckert
> 1990 WB-40"smoke N Mirrors"
> Niceville, FL
>
> ----- Original Message -----
> From: g_man1146
> To: WanderlodgeForum@yahoogroups.com
> Sent: Monday, February 19, 2007 9:08 PM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
> Gregory,
>
> On the later model Series 60's the fan bypass valve diverts
> hydraulic oil around the fan motor to allow the fan to run at a
> lower speed by sending the oil back without going through the
> fan "motor". If the bypass valve fails, you get full RPM of the
fan
> as all of the oil is directed to the fan motor. This has nothing
to
> do with a filter bypass. The bypass valve can also be tested by
> plugging the return line that goes to the bypass valve thus
forcing
> all oil through the fan motor.
>
> Rich D. '99LXi43' CT
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Yes.
> >
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Nicevile, FL
> >
> >
> > ----- Original Message -----
> > From: Gregory OConnor
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 8:02 PM
> > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> >
> >
> > David, Bypass and override are two independent features. I
> believe
> > bypass is a safety feature for a clogged hydro oil filter.
> Bypass is
> > not triggered by the override dash switch
> > GregoryO'Connor
> > 94ptRomolandCa
> >
> > --- In WanderlodgeForum@yahoogroups.com, David Brady
> > wrote:
> > >
> > > Hi Rich,
> > >
> > > Thanks for the help. When I return to the bus I'll try your
> test.
> > > I guess if the fan speed increases, then the problem is
between
> > > the dash switch and the "bypass valve". Alas, no wiring
> schematics..
> > > I'll let you know what happens.
> > >
> > >
> > > David B
> > > '02 LXi, Smokey
> > > NC
> > >
> > > g_man1146 wrote:
> > > > Hi David,
> > > >
> > > > AS others have stated, a fan over-ride failure should fault
> to
> > high
> > > > speed. If you are not getting high fan speed with the air
> > conditioner
> > > > on or with the switch set to "over-ride" locate (assuming
> Detroit
> > S60)
> > > > a connector plug at the rear of the engine compartment
> (closest
> > to rear
> > > > bumper) on the fan side. You should see a hydraulic hose
> from the
> > fan
> > > > motor to this block (bypass valve) and wires coming from
it.
> If
> > you
> > > > disconnect the connector plug on these wires, the fan
should
> come
> > up to
> > > > full RPM. (ROAR) If it increases but not fully, the problem
> may
> > lie
> > > > with the hydraulic pump which is attached to the PTO on the
> curb
> > side
> > > > of the Allison or with the hydraulic bypass valve. BB makes
> > changes all
> > > > the time and my coach (3 years older) may not be set up the
> same.
> > If
> > > > you are not overheating on long hills everything may be
> normal. I
> > > > experienced an overheating situation only in extreme
> situations
> > and
> > > > determined the problem to be a faulty hydraulic pump
> supplied as
> > part
> > > > of the PTO recall from BB. The pump did not have sufficient
> > capacity to
> > > > run the fan at full speed. They supplied a new pump and
> labor to
> > > > install. The fan motor is actually rated at about 40 HP at
> full
> > > > capacity. No wonder it is designed to cut back when not
> needed!
> > > >
> > > > Rich D. '99LXi43' CT
> > > >
> > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
>
> > wrote:
> > > >
> > > >> Folks,
> > > >>
> > > >> On my '02 LXi, with the engine at idle, the fan seems to
> rotate
> > > >> at 400 rpm or so (give or take, lol), when I enable the
> override
> > > >> switch there doesn't seem to be any change in fan speed.
> Should
> > > >> there be? or are there other parameters at work hear;
i.e.,
> > engine
> > > >> temp, etc. What are the common failure modes of the fan
> override?
> > > >>
> > > >> Thanks,
> > > >> David Brady
> > > >> '02 LXi, Smokey
> > > >> NC
> > > >>
> > > >>
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> [Non-text portions of this message have been removed]
>
>
>
>
>
> [Non-text portions of this message have been removed]
>





[Non-text portions of this message have been removed]

[David Brady]

Leroy,

From a circuit standpoint, I think you're looking for an Open Collector
Output on each of the signals: a/c, override switch, and alarmstat. All
three would then be tied together and pulled up with a power source
and a resistor. This signal could then be fed into the bypass switch.

When all signals are off, the pull up resistor supplies power to the bypass
enabling the piston and the slow fan speed. When one or more of the input
signals drives it's Open Collector output to ground, the pull up
resistor will
be driven to ground and in turn the input to the bypass switch will be
ground
resulting in the release of the piston and a high fan speed.

If the power source goes away, then the input to the bypass switch loses
it's
voltage and the bypass defaults to high fans speed.

This can easily be implemented with transistors, relays are another story...

David Brady
'02 LXi, Smokey
NC

Leroy Eckert wrote:
> Ok, thanks. Now all I have to figure out is how any one of the three
components disables the other two when in high mode. Somehow, the a/c and
override switch must be tied to the Alarmstat NC sensor . I just haven't figured
that one out. I want to make an electrical drawing of my system. If I figure it
out, I'll post it.
>
> Thanks,
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Niceville, FL
>
>
>
> ----- Original Message -----
> From: g_man1146
> To: WanderlodgeForum@yahoogroups.com
> Sent: Tuesday, February 20, 2007 9:11 AM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> Leroy,
> You are correct; the fan bypass defaults to closed, thereby forcing
> all of the pump output through the fan motor. Cool temperatures, air
> conditioner "ON" or "Fan Override" switch "ON" all hold the bypass
> valve open allowing oil to flow around the fan motor. When I was
> attempting to diagnose what turned out to be a defective pump, BB
> sent me a diagram and test procedure to follow. They said the LXi
> shared the same system as the "LTC" commercial coach.
>
> Rich D. '99LXi43' CT
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Rich: I have a question on the bypass valve if you know. I do not
> have a drawing of the valve.
> >
> > As I understand the system, the fan is normally in idle(bypass)
> mode until one of three things happen. The alarmstat activates high
> mode based on water temperature, the fan override(manually by humans
> or grandkids) activates high mode or the chassis a/c on switch
> activates high mode.
> > Does the fan bypass valve default to fan high mode? . That would
> make sense otherwise the system would overheat with valve or
> electrical failure. If so, one could conclude that the piston in the
> valve is actuated by continuous power in the bypass position and the
> fan override, a/c switch and alarmstat cuts power off to it and it is
> spring loaded to full fan mode.
> >
> > If you know. Thanks. Trying to learn more here.
> >
> >
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Niceville,FL
> >
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: Leroy Eckert
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 9:35 PM
> > Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch
> >
> >
> > That was to Greg, but I think we are all speaking of the same
> thing, just a different component in the system with a bypass. The
> fan control valve has a bypass as does the Parker filter. The
> override sends a message so to speak to the valve to stop the bypass
> and get into high mode. So does the chassis a/c on switch. If the
> valve is bad, the fan will not spool up.
> >
> > Leroy Eckert
> > 1990 WB-40"smoke N Mirrors"
> > Niceville, FL
> >
> > ----- Original Message -----
> > From: g_man1146
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 9:08 PM
> > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> >
> > Gregory,
> >
> > On the later model Series 60's the fan bypass valve diverts
> > hydraulic oil around the fan motor to allow the fan to run at a
> > lower speed by sending the oil back without going through the
> > fan "motor". If the bypass valve fails, you get full RPM of the
> fan
> > as all of the oil is directed to the fan motor. This has nothing
> to
> > do with a filter bypass. The bypass valve can also be tested by
> > plugging the return line that goes to the bypass valve thus
> forcing
> > all oil through the fan motor.
> >
> > Rich D. '99LXi43' CT
> >
> > --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> > wrote:
> > >
> > > Yes.
> > >
> > > Leroy Eckert
> > > 1990 WB-40"Smoke N Mirrors"
> > > Nicevile, FL
> > >
> > >
> > > ----- Original Message -----
> > > From: Gregory OConnor
> > > To: WanderlodgeForum@yahoogroups.com
> > > Sent: Monday, February 19, 2007 8:02 PM
> > > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> > >
> > >
> > > David, Bypass and override are two independent features. I
> > believe
> > > bypass is a safety feature for a clogged hydro oil filter.
> > Bypass is
> > > not triggered by the override dash switch
> > > GregoryO'Connor
> > > 94ptRomolandCa
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, David Brady
> > > wrote:
> > > >
> > > > Hi Rich,
> > > >
> > > > Thanks for the help. When I return to the bus I'll try your
> > test.
> > > > I guess if the fan speed increases, then the problem is
> between
> > > > the dash switch and the "bypass valve". Alas, no wiring
> > schematics..
> > > > I'll let you know what happens.
> > > >
> > > >
> > > > David B
> > > > '02 LXi, Smokey
> > > > NC
> > > >
> > > > g_man1146 wrote:
> > > > > Hi David,
> > > > >
> > > > > AS others have stated, a fan over-ride failure should fault
> > to
> > > high
> > > > > speed. If you are not getting high fan speed with the air
> > > conditioner
> > > > > on or with the switch set to "over-ride" locate (assuming
> > Detroit
> > > S60)
> > > > > a connector plug at the rear of the engine compartment
> > (closest
> > > to rear
> > > > > bumper) on the fan side. You should see a hydraulic hose
> > from the
> > > fan
> > > > > motor to this block (bypass valve) and wires coming from
> it.
> > If
> > > you
> > > > > disconnect the connector plug on these wires, the fan
> should
> > come
> > > up to
> > > > > full RPM. (ROAR) If it increases but not fully, the problem
> > may
> > > lie
> > > > > with the hydraulic pump which is attached to the PTO on the
> > curb
> > > side
> > > > > of the Allison or with the hydraulic bypass valve. BB makes
> > > changes all
> > > > > the time and my coach (3 years older) may not be set up the
> > same.
> > > If
> > > > > you are not overheating on long hills everything may be
> > normal. I
> > > > > experienced an overheating situation only in extreme
> > situations
> > > and
> > > > > determined the problem to be a faulty hydraulic pump
> > supplied as
> > > part
> > > > > of the PTO recall from BB. The pump did not have sufficient
> > > capacity to
> > > > > run the fan at full speed. They supplied a new pump and
> > labor to
> > > > > install. The fan motor is actually rated at about 40 HP at
> > full
> > > > > capacity. No wonder it is designed to cut back when not
> > needed!
> > > > >
> > > > > Rich D. '99LXi43' CT
> > > > >
> > > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
> >
> > > wrote:
> > > > >
> > > > >> Folks,
> > > > >>
> > > > >> On my '02 LXi, with the engine at idle, the fan seems to
> > rotate
> > > > >> at 400 rpm or so (give or take, lol), when I enable the
> > override
> > > > >> switch there doesn't seem to be any change in fan speed.
> > Should
> > > > >> there be? or are there other parameters at work hear;
> i.e.,
> > > engine
> > > > >> temp, etc. What are the common failure modes of the fan
> > override?
> > > > >>
> > > > >> Thanks,
> > > > >> David Brady
> > > > >> '02 LXi, Smokey
> > > > >> NC
> > > > >>
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>

[Leroy Eckert]

Thanks, I had concluded that some sort of collector box or terminal strip would
be needed because the three components must have power until actuation. Since
any one of the three can independently place the fan in high mode I couldn't
follow it. I called BB and Jessie said he would see if he can find a schematic.
Everything works fine now but I would like to document it in my Bluebox just in
case, primarily because I intend to sleep between now and the time of failure.
lol

Thanks,

Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Niceville, FL




----- Original Message -----
From: David Brady
To: WanderlodgeForum@yahoogroups.com
Sent: Tuesday, February 20, 2007 5:48 PM
Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch


Leroy,

From a circuit standpoint, I think you're looking for an Open Collector
Output on each of the signals: a/c, override switch, and alarmstat. All
three would then be tied together and pulled up with a power source
and a resistor. This signal could then be fed into the bypass switch.

When all signals are off, the pull up resistor supplies power to the bypass
enabling the piston and the slow fan speed. When one or more of the input
signals drives it's Open Collector output to ground, the pull up
resistor will
be driven to ground and in turn the input to the bypass switch will be
ground
resulting in the release of the piston and a high fan speed.

If the power source goes away, then the input to the bypass switch loses
it's
voltage and the bypass defaults to high fans speed.

This can easily be implemented with transistors, relays are another story...

David Brady
'02 LXi, Smokey
NC

Leroy Eckert wrote:
> Ok, thanks. Now all I have to figure out is how any one of the three
components disables the other two when in high mode. Somehow, the a/c and
override switch must be tied to the Alarmstat NC sensor . I just haven't figured
that one out. I want to make an electrical drawing of my system. If I figure it
out, I'll post it.
>
> Thanks,
>
> Leroy Eckert
> 1990 WB-40"Smoke N Mirrors"
> Niceville, FL
>
>
>
> ----- Original Message -----
> From: g_man1146
> To: WanderlodgeForum@yahoogroups.com
> Sent: Tuesday, February 20, 2007 9:11 AM
> Subject: [WanderlodgeForum] Re: Coolant fan override switch
>
>
> Leroy,
> You are correct; the fan bypass defaults to closed, thereby forcing
> all of the pump output through the fan motor. Cool temperatures, air
> conditioner "ON" or "Fan Override" switch "ON" all hold the bypass
> valve open allowing oil to flow around the fan motor. When I was
> attempting to diagnose what turned out to be a defective pump, BB
> sent me a diagram and test procedure to follow. They said the LXi
> shared the same system as the "LTC" commercial coach.
>
> Rich D. '99LXi43' CT
>
> --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> wrote:
> >
> > Rich: I have a question on the bypass valve if you know. I do not
> have a drawing of the valve.
> >
> > As I understand the system, the fan is normally in idle(bypass)
> mode until one of three things happen. The alarmstat activates high
> mode based on water temperature, the fan override(manually by humans
> or grandkids) activates high mode or the chassis a/c on switch
> activates high mode.
> > Does the fan bypass valve default to fan high mode? . That would
> make sense otherwise the system would overheat with valve or
> electrical failure. If so, one could conclude that the piston in the
> valve is actuated by continuous power in the bypass position and the
> fan override, a/c switch and alarmstat cuts power off to it and it is
> spring loaded to full fan mode.
> >
> > If you know. Thanks. Trying to learn more here.
> >
> >
> > Leroy Eckert
> > 1990 WB-40"Smoke N Mirrors"
> > Niceville,FL
> >
> >
> >
> >
> >
> >
> > ----- Original Message -----
> > From: Leroy Eckert
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 9:35 PM
> > Subject: Re: [WanderlodgeForum] Re: Coolant fan override switch
> >
> >
> > That was to Greg, but I think we are all speaking of the same
> thing, just a different component in the system with a bypass. The
> fan control valve has a bypass as does the Parker filter. The
> override sends a message so to speak to the valve to stop the bypass
> and get into high mode. So does the chassis a/c on switch. If the
> valve is bad, the fan will not spool up.
> >
> > Leroy Eckert
> > 1990 WB-40"smoke N Mirrors"
> > Niceville, FL
> >
> > ----- Original Message -----
> > From: g_man1146
> > To: WanderlodgeForum@yahoogroups.com
> > Sent: Monday, February 19, 2007 9:08 PM
> > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> >
> > Gregory,
> >
> > On the later model Series 60's the fan bypass valve diverts
> > hydraulic oil around the fan motor to allow the fan to run at a
> > lower speed by sending the oil back without going through the
> > fan "motor". If the bypass valve fails, you get full RPM of the
> fan
> > as all of the oil is directed to the fan motor. This has nothing
> to
> > do with a filter bypass. The bypass valve can also be tested by
> > plugging the return line that goes to the bypass valve thus
> forcing
> > all oil through the fan motor.
> >
> > Rich D. '99LXi43' CT
> >
> > --- In WanderlodgeForum@yahoogroups.com, "Leroy Eckert"
> > wrote:
> > >
> > > Yes.
> > >
> > > Leroy Eckert
> > > 1990 WB-40"Smoke N Mirrors"
> > > Nicevile, FL
> > >
> > >
> > > ----- Original Message -----
> > > From: Gregory OConnor
> > > To: WanderlodgeForum@yahoogroups.com
> > > Sent: Monday, February 19, 2007 8:02 PM
> > > Subject: [WanderlodgeForum] Re: Coolant fan override switch
> > >
> > >
> > > David, Bypass and override are two independent features. I
> > believe
> > > bypass is a safety feature for a clogged hydro oil filter.
> > Bypass is
> > > not triggered by the override dash switch
> > > GregoryO'Connor
> > > 94ptRomolandCa
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, David Brady
> > > wrote:
> > > >
> > > > Hi Rich,
> > > >
> > > > Thanks for the help. When I return to the bus I'll try your
> > test.
> > > > I guess if the fan speed increases, then the problem is
> between
> > > > the dash switch and the "bypass valve". Alas, no wiring
> > schematics..
> > > > I'll let you know what happens.
> > > >
> > > >
> > > > David B
> > > > '02 LXi, Smokey
> > > > NC
> > > >
> > > > g_man1146 wrote:
> > > > > Hi David,
> > > > >
> > > > > AS others have stated, a fan over-ride failure should fault
> > to
> > > high
> > > > > speed. If you are not getting high fan speed with the air
> > > conditioner
> > > > > on or with the switch set to "over-ride" locate (assuming
> > Detroit
> > > S60)
> > > > > a connector plug at the rear of the engine compartment
> > (closest
> > > to rear
> > > > > bumper) on the fan side. You should see a hydraulic hose
> > from the
> > > fan
> > > > > motor to this block (bypass valve) and wires coming from
> it.
> > If
> > > you
> > > > > disconnect the connector plug on these wires, the fan
> should
> > come
> > > up to
> > > > > full RPM. (ROAR) If it increases but not fully, the problem
> > may
> > > lie
> > > > > with the hydraulic pump which is attached to the PTO on the
> > curb
> > > side
> > > > > of the Allison or with the hydraulic bypass valve. BB makes
> > > changes all
> > > > > the time and my coach (3 years older) may not be set up the
> > same.
> > > If
> > > > > you are not overheating on long hills everything may be
> > normal. I
> > > > > experienced an overheating situation only in extreme
> > situations
> > > and
> > > > > determined the problem to be a faulty hydraulic pump
> > supplied as
> > > part
> > > > > of the PTO recall from BB. The pump did not have sufficient
> > > capacity to
> > > > > run the fan at full speed. They supplied a new pump and
> > labor to
> > > > > install. The fan motor is actually rated at about 40 HP at
> > full
> > > > > capacity. No wonder it is designed to cut back when not
> > needed!
> > > > >
> > > > > Rich D. '99LXi43' CT
> > > > >
> > > > > --- In WanderlodgeForum@yahoogroups.com, David Brady
> >
> > > wrote:
> > > > >
> > > > >> Folks,
> > > > >>
> > > > >> On my '02 LXi, with the engine at idle, the fan seems to
> > rotate
> > > > >> at 400 rpm or so (give or take, lol), when I enable the
> > override
> > > > >> switch there doesn't seem to be any change in fan speed.
> > Should
> > > > >> there be? or are there other parameters at work hear;
> i.e.,
> > > engine
> > > > >> temp, etc. What are the common failure modes of the fan
> > override?
> > > > >>
> > > > >> Thanks,
> > > > >> David Brady
> > > > >> '02 LXi, Smokey
> > > > >> NC
> > > > >>
> > > > >>
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Yahoo! Groups Links
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>





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