RE: V8 radiator electric cooling fan operation

["Curry, Rene" <Rene@SINECO.com>]

Ralph,
I know nothing about an Audi V8, but if it has the same 3 position
radiator thermal switch as my 84 Audi 5000S Turbo you may want to
consider installing your own simple wiring harness with two relays and
use only the medium & high fan speeds.  By using direct battery voltage
it would also act as the "ignition-off" cool down mode. Add a fusible
link or circuit breaker and viola.  This may not be the correct fix, but
it would be cheap & dependable.  You should be able to do it for under
$50.00 USD.   I may even have a couple relays at home you could have if
your in a jam & I could sketch a simple wiring schematic.  I added an
electric fan to my 71 Chevelle work car to increase fuel economy since
it sees over 100 miles a day of freeway driving (fan is rarely needed)
and the relay has worked flawlessly for the past two years.
 
Rene Curry
Grosse Ile, MI

> Ralph  Cook wrote: 
>
>Scott,
>I want to thank you for your response. As it turns out, we did all the
>tests as you describe and the electric fan works in the test mode
>(bypassing the instrument panel computer control.) The fans still do not
>function when the signal is processed as per normal conditions. This
>tells me I need the instrument panel computer unit. I am told that a new
>unit is $1,200.00 give or take. Are there any re-builts out there??
>Ralph Cook 
>
>Scott Mockry wrote:
>> 
>> Ralph,
>> 
>> If you are referring to the electric radiator fan, and none of the fan
>> speeds are working ...
>Yup,..thats the problem except that I am told that the fan will work if
>the A/C is on...Agree?
>
>Then remove the 400 ohm
>> resistors and insert a 100 ohm resistors across both connectors, NOW the
>> Instrument panel computer is supposed to step through  and turn on the 1st,
>> 2nd, and then the 3rd speeds of the radiator fan.
>> 
>> (Yes, believe it or not, the instrument panel computer controls the
>> radiator fan)
>> 
> Dyment Publications 1-800-544-8021 used to carry the V8 repair manual
>on micro-fiche for about $30, the printed manual is no longer available,
>> although there are some copies floating around Audi cyberspace.
>> 
>> HTH
>> Scott Mockry
>> 
>> >My 90V8Q has a fan activation problem. The three stages of fan do not
>> >function and my technical goo-roos tell me that the problem is in a
>> >little processor module within the INSTRUMENT CLUSTER! If I want it
>> >right again I must shell out $1200.00 for a replacement instrument
>> >cluster...Ouch! Any listers been through this?
>> >
>> >Ralph Cook
>> >90V8Q 194,000 mi, commuter wheels
>> >93V8Q  43,000 Mi, Sunday go ta meetin' car