Climate Control Fan inconsistant 88 5000

[BSWANN@arinc.com]

Greetings,

I just replaced the radiator fan in my 5000 Wagon which had seized up. 
 I hope this was done before any wiring damage.  

Now I notice that my climate control fan doesn't operate on demand.  
When I first start up with engine cool it works - sometimes.

After the car is warmed up - can't get it to operate.  I can hear the 
compressor clutch kick on if I set it for AC and if set to heat can 
hear the vents set for heat, etc. just the fan doesn't go on.

Other notable symptoms:

Not sure if radiator fan goes on during normal driving, as a couple of 
times was stuck in gridlock, the temp gauge started to rise but I 
never heard radiator fan kick on and the warning light came on just 
before I would get onto the highway and cool back down again.  The 
radiator fan kicks on with the AC, and afterrun works.  Possible 
Resistor Pack problem?

I looked at a generic wiring diagram for AUDI 5000's ( havent got a 
Bently yet) could not find the climate control fan, but noticed the 
following:

Seat Belt relay has leads going to
   Climate control
   Cruise Control (not working )
   Under Hood light (not working)
   Antenna??? (never can get good reception)

Is it possible that this is the source of this anomoly?  Where is this 
relay?  By the way I did check all fuses.

I'd appreciate if anyone can provide me with some additional clues.

Thanks,

Ben Swann
'85 4KSQ
'86 5KCSQT (parts or restore?)
'87 5KCSQT Wagon
'88 5KS Wagon