1991 Audi 200 Turbo A/C failure

[JCAudi200]

Hello all. I recently had my A/C system converted over for R134A and unfortunately, it now will not produce any cold air. I have had the vehicle looked at three times and subsequently purgered and recharged accordingly to no avail. Is there anything that my mechanic may be overlooking as no leaks have been identified nor any problems with the compressor. Any assistance is appreciated.

[Harvey Smith]

Hi JC. I just converted my 5000 over to the new AC Stuff and had quite a time getting things working properly. There was a need for my own work along with the Bentley manual. Also a need to read the electrical drawings in Bentley which are really great. I think my 5000 is fairly close to your 200 in design. My manual, however, does not get into the 100, 200 series.

Some major check points:
1) Does the blower blow out the center vents when set to Cool.
2) Does the Compressor run
3) There is a vacuum operated thingy under the hood near the back of the engine that must turn off the hot water to the heater core when the A/C is set to cool. Is that working.
4) If the 200 has that silly plastic junk cowel cover over the AC stuff under the hood near the dash you will need to remove it... very carefully so as not to damage it. ( Most parts on my Audi are excellent, fortunately)
There should be a very cold pipe under there if the A/C circuit is alive.
5) On the passenger side under cowel cover there is a large flap that should be closed when A/C set to cool and it should open when set to Heat.
6) Near the center under the cowel cover there is a large heater thing where the heater fan is located.. Does the cable from inside the car open and close this unit. Cable should move out or in depending if set to Heat or Cool. That is driven by a controller inside via the Heater/AC Control box on the console..

7) The A/C Heater uses vacuum from the manifold to operate. Make sure the service shop did not knock one of these off or whatever.
8) Under that cowel there is a silver cannister (dryer).. This should have been replaced when the conversion was done according to my shop.


The A/C System is not always an easy game!.. Mine works great now.. Good luck with yours.

[trev0006]

look expensive

[audiqv8]

Originally Posted by JCAudi200

Hello all. I recently had my A/C system converted over for R134A and unfortunately, it now will not produce any cold air. I have had the vehicle looked at three times and subsequently purgered and recharged accordingly to no avail. Is there anything that my mechanic may be overlooking as no leaks have been identified nor any problems with the compressor. Any assistance is appreciated.

A little more information is needed.

Does the AC works while driving on the highway, but stop working while driving on local streets?

Did the mechanic use a set of manifold gauges to see the HI and Low side pressure?

Is the compressor turning on?