87 QSW - Running Hot; Fan not working

[JGriff]

HAudi folks!! It's Jim Griffin... remember me!!?? :-)

It's been a long, long time since I've been on the main list!! I've been 
subbed to the V6-12V list, but not the main list, due to the volume of 
e-mails, but I browse the archives every now and then. I hope all is well 
with everyone.

I've subbed to the main list because I need the collective wisdom of my 
fellow Audifans. So, here goes:

Subject - 1987 Quantum Syncro (a.k.a. 4000 Quattro Avant); 2.2l 5-cylinder; 
non-torsen quattro (i.e. locking diffs!!)

Problem - Running hot... temp gauges climbs and climbs etc.; fan does not 
come on while car is running; it comes on afterwards (i.e. after-run seems 
to work okay), although recently, that seems to have stopped working also 
(at least yesterday it didn't come on).

I've done just about everything (well, a lot... if not absolutely 
everything) that I can think of so far:

- replaced the thermoswitch at the bottom of the radiator
- replaced the fan relay
- replaced the fan
- replaced the thermostat
- replaced the temp sensor
- changed the coolant (by default... with all of this work, I sure drained 
out quite a bit)
- attempted to clean and re-connect some connections here and there that 
looked nasty
- the water pump was replaced with the timing belt a little while ago... 
probably 20k miles ago

I'm at my wits end. This is getting quite frustrating!!

A couple of questions:

- there is a small (ceramic?) resistor mounted on the fan, with two wires 
coming off of it (i.e. it is "inline"). Does anyone know what it is for, 
and could that be the problem? The part # is 171 959 493, FWIW (i.e. those 
with ETKA)

- I looked in the Bentley, at the wiring diagrams, to see if there is 
another thermoswitch or something, and according to that, there appears to 
be another (i.e. other than the after-run thermoswitch) somewhere. Is the 
Bentley wrong, or is there another switch somewhere that controls the fan 
while the car is running?

If I can't figure out what the problem is, I'm thinking of just wiring in a 
two-position (for low and high speeds), cockpit-controlled switch so that I 
can at least cool the car down manually. (Has anyone ever done this? Any 
tips/tricks etc.? I figure I'll use a relay, for extra peace-of-mind).

All thoughts, suggestions, advice, and sympathy is greatly appreciated.

BTW, I will be selling the car, once I get this problem fixed. This is 
really the only problem with the car right now (other than the A/C that 
isn't working). So... if anyone is interested in a great QSW.... please 
feel free to get in touch. Here is a page about the car:

http://www.geocities.com/MotorCity/4475/myQSW.html

I'm selling it because I made a deal with the Mrs... a 1973 Porsche 914 in 
exchange for the QSW.

FWIW, here is a page about the 914:
http://jgriff.freeservers.com/Porsche914.htm

P.S. FWIW,  this was Unka Bart's QSW!! I'd love to see it stay in the 
"family", so someone on this list, please buy it before I end up posting it 
for sale to the unappreciative masses!! :-)

Thanks.

Jim

                  Jim Griffin
           JGriff at JGriff.com
          http://www.JGriff.com
        http://pobox.com/~jgriff
       '87 VW Quantum Syncro
              '92 Audi 100S
        '73 Porsche 914-4 2.0
        '01 Subaru Forester S