Coolant fan override switch

[Gregory OConnor]

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
> >
> >
> >
> >
> >
> >
>
>
>
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