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
>
>
>
>
>
>



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