AC cutting out -air gap checked

[whlav]

Air conditioner fits all the operating symptoms described inthe Forumfor the clutch shim adjustment i.e. runs fine and then cuts out and starts blowing warm air.Had system checked. Fully charged,no leaks. Had AC shims checked,in tolerance. Cooling fan checks out OK. Compressor clutch did not engage when checked at home. Took it to local shop and worked fine over three days of checking,blew cool all the time. Any suggestions? Seems to only happen when I'm going down the road. Frustrated!

 

[jcostantino]

Check the clutch when it blows hot to see if it's engaged and spinning. I've got the same problem you do but when it happens it's usually inconvenient to get out and unlock the hood and fiddle with it so I haven't seen yet.

The dealer charged me $65 to tell me that the system pressure is fine and that it's "in spec" even though it poops out and blows hot until it feels like blowin cold again.

Jeff

 

[Larry Bialecki]

Measure the current through the clutch coil when it is blowing hot and should be cool. It there is current and the clutch is not engaged than the gap is still too large. In my case I found that when it was hot under the hood the resistance of the clutch coil went up to the point that there was not enough current through the coil to pull in the clutch. I =E/R. With not enough current there was not enough magantic field to pull in the clutch with the gap that existed. I just reduced the gap (easy job if you have the tools or make them) and thing worked great from there on. If there is no current than there is a problem with the electronic switching contro module or you are low on freon. By the way R-134A works well in the system, just make sure you drain the old compressor oil before puttion in R-134A.

 

[pjtoledo]

As the last post alluded to, the coil may be the problem. Does the AC work for a few minutes, then quit? Will it again work at freeway speeds? The coil gets hot from engine heat, and quits working. If driving 75 or 80 there is enough air to keep it cool and the AC again works. Had this same problem on several cars, worth looking into. The hardest part is checking the current going thru the AC coil during failure, I had to rig a connector and wires to test it. Just did my 92 a couple of weeks ago for this problem, and the 95 is in need of it now.

Perry Toledo,Ohio

 

[whlav]

Picked my car up from local shop on Friday after getting reassured that a/c system was fine (another $60.00 diagnosis fee) this was after I showed them a copy of the "setting air gap" as posted in the Forum. They were not aware of the procedure but checked the gap and said it was in tolerance. Of course the same problem still exists. Thanks to you who have replied.

The clutch was in and turning today when it started to blow hot again. I'll take pjtoledo's advice and take her out on freeway run to see if it starts to cool down again at highway speed . Going to narrow this sucker down yet!

 

[projectSHO89]

I found the hard way that it can appear that the clutch is turning, but the compressor shaft is not.

My guess is it would take a long inspection mirror to actually look in there to observe the center bolt that connects to the shaft.

Otherwise, catch it in failure mode and check the high and low side pressures with a manifold guage set. If the pressures are the same, the compressor shaft is not turning even if the clutch hub makes it look like it is.

Steve
89

 

[whlav]

Drove in town traffic for about 30 minutes wcold air then started blowing hot again. Tried pjtoledo's suggestion and drove about 30 miles onI-65 at 70plus with no change . Shut a/c off for 5 minutes and had cold air all the way back to town on the Interstate. Got to townand it crapped out again. Thanks for all the suggestions. Will keep trying.

 

[Slo-Sho]

Is the condenser free of debris? May be an intermittent electrical connection. Those weather pack connectors can come loose over time. Good luck man, I know this must be a real PITA.

 

[pjtoledo]

whlav:
Drove in town traffic for about 30 minutes wcold air then started blowing hot again. Tried pjtoledo's suggestion and drove about 30 miles onI-65 at 70plus with no change . Shut a/c off for 5 minutes and had cold air all the way back to town on the Interstate. Got to townand it crapped out again. Thanks for all the suggestions. Will keep trying.

Those are the symptoms of a failing coil. So far I am 4 for 4 in fixing that problem with a new coil. That's 1 VW Jetta, my 92 SHO twice, and just last week my wifes 95 SHO. I had to rig a wiring harness that allowed me to monitor both the voltage and current as the car was being driven the first time, the others I just acted on the symptoms. Keep us posted.

Perry Toledo,Ohio

 

[SHOMA]

Hey Im no expert, but I cant believe no one has mentioned this yet... DO this: PRess off and floor at the same time, release and immediately push automatic once... it will run the self test...If my guess is right, it will come up with a code 02... This is the blend door actuator... MY 94 ATX did the SAME thing, and I never did fix it, hbut it is not a very bad repair from what I was told. It will eventually quit for good.. The part is the door that blends the cold and hot air, it gets stuck on hot, and thats why you get the hot air... I know with mine, it was HOTTER THAN HOT! Check out the self test, push off/floor at the same time, release and press automatic once... it will run its test (about 1 min).... If it comes up with the 888 and all lights lit, than it checked out good, but if it comes up with a code 02, as I had, it is the blend door actuator!I was told it is located on top of the evaporator case, but hey if its as hot there as it is here, it doesnt matter where it is! Supposedly a $40-$45 part...Let me know if it works, Im by no means an expert, but I have had my share of problems with SHO's!
GOOD LUCK, keep me posted!
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P.S. my car was running when I did it, so try it with it running..