[s-cars] Urs4 Elec Rad Fan Probs

[Sean Douglas]

Iain:

The fan is controlled by 2 different switches, one in the radiator which
monitors temp while the engine is running to tell the fan to run at low
or high speed, the 2nd switch in the coolant pipe just above the
thermostat to tell the fan and the electric water pump to come on after
the engine is off. It only comes on if the coolant is above 102F (IIRC)
and for a max of 10 minutes. Its timed by a relay. If the fan doesn't
shut off by itself after turning off the engine, then there is something
wrong with the timer relay.

When you touched the 2 wires together, you didn't say that the fan came
on as well as the pump.

I would look at either the temp switch or the timer relay being the
culprit.

FWIW, it takes quite a lot of heat to get the pump and fan to come on,
in my 1997 it rarely came on (only once or twice in the summer after
driving hard). To cure this issue, I installed a low-temp switch to
invoke the after run fan and pump at a lower temp, now it comes on about
50% of the time.

Sean Douglas
1997 Audi S6//RS2-spec
1990 Audi 90 quattro 20v


> -----Original Message-----
> From: s-car-list-bounces at audifans.com 
> [mailto:s-car-list-bounces at audifans.com] On Behalf Of 
> iain.atkinson at tesco.net
> Sent: Wednesday, May 25, 2005 11:19 PM
> To: s-car-list at audifans.com
> Subject: [s-cars] Urs4 Elec Rad Fan Probs
> 
> 
> Folks
> 
> i have a problem where this fan does and then doesn't work. 
> After i shut down the car 99% of the time it never kicks in, 
> neither does it do it with the car running and up to temp. 
> However what it does do is kick in a long time after the car 
> has been shut down and then won't switch off draining the 
> battery, like this morning at 6.45am when i try to take the 
> wife  to work.
> 
> What else controls this and what should i replace??? I have 
> already replaced the 2 relays in the box in the plenum 
> chamber area. Afterun coolant pump works fine, bentley does 
> give a procedure where you take the 2 wires off a sensor for 
> the afterun coolant pump and touch them together, done this 
> coolant pump runs fine.
> 
> Cheers
> 
> Iain
> 
> _______________________________________________
> S-CAR-List mailing list
> S-CAR-List at audifans.com 
> http://www.audifans.com/mailman/listinfo/s-> car-list
>