Re: Re[2]: A/C problems

[walter@quattro.corp.inmet.com (Walter Meares)]

> 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)

The manual system for my 85 4000sq forces the blower to low speed when the A/C
switch goes on, even if the fan switch is "off".  I didn't get a chance to
check Bentley to see how this interlock is accomplished, but I'd guess you
either have a defective AC switch or possibly a stuck/broken relay (I'd guess
the A/C switch drives a relay that operates both the compressor and the blower
switch over-ride.

If your fuse box identifies an AC relay, you might try pulling it to see if
both compressor and fan go off, and see if the heater works absent the relay.
If so you can get the problem (which still could be either the switch or the
relay) fixed at your leisure.  If you're mechanically/electrically inclined,
testing the switch and relay is not too difficult.

Of course if there's no relay it almost has to be the switch.  But it doesn't
seem likely that Audi would have omitted a relay, given the chance to design
one into the circuit.  :-)

Good luck!

> 
> Thanks for the help
> Heidi
> 

Walter