Re: Re[2]: A/C problems

[zm@mhcnet.att.com (Zafer Mehmood [209])]

> 
> My original posted problem: (1) a/c switch shuts off - light goes out and 
> switch position moves, but a/c continues to blow cold air and (2) off 
> position for blower still blows on low - will not shut off.
> 
> There have been responses about the Electronic Climate Control System, but 
> unfortunately (or fortunately!) my 88 90Q has the standard/manual setup.  
> 
> Are any of the parts mentioned common to both systems and if not, what could 
> be failing and causing the a/c and blower to stay on in a system without 
> climate control?  
> 
> Any suggestions for how to narrow it down (sorry - no Bentley)
> 

Heidi,
	I posted earlier about the Electronic CC system not knowing your
car had the manual system. Unfortunately, I am not familiar with the
manual system and my Bentley manual for the 5000 series covers only the
Electronic systems. Without looking at the wiring diagram for your car,
its very hard to pinpoint where the problem may lie. On most manual systems,
both the A/C switch and the blower switch should be on for the A/C
compressor to turn on and generate cold air. Since it is unlikely that
both your switches are bad and stuck in the ON position, it may be
a short in the wiring somewhere. Seems like something is bypassing both
switches. 

The other possibility is that what you perceive as cold air is really cool
outside air and the A/C compressor is really not ON and only the blower
switch is bad. Check to see if the A/C compressor is running with the
engine running. The A/C compressor pulley always rotates and a clutch
cycles the compressor on/off every few tens of seconds. Look to see if the
front of the compressor pulley (usually has a triangular plate) is turning
or stationary. If the compressor is not on, then you are probably looking
at a bad blower fan switch. If the compressor is indeed on and cycling,
then more troubleshooting will be necessary. Since you don't have the Bentley, 
take the car into the Audi dealer or a competent Audi mechanic.

- Zafer

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Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ