ddemier7

Hey guys,

My 2007 Chevy Impala SS 5.3ltr with 134,000 miles was involved in a minor front end collision. Part of the repair was to replace the condenser and fan assembly which I did because i'm a collision tech. The car is all fixed now and I just had the A/C and alignment done by a professional shop. The A/C took a charge and has the correct pounds in it, however there is no cold air blowing through any of the vents. Any ideas what could be causing this issue? perhaps a faulty blend door? The compressor (clutch) is kicking on when the A/C is on.

thanks for any professional suggestions.

tech2

feel the high and low side ac lines. there should be a noticeable hot line and cold line. if yes...the is producing cold air and the problem is probably a blend door issue...if not the is not producing cold air. check the high and low side pressures for diagnostic information.

the hvac system has diagnostic capabilities...you can check for body codes.

ddemier7

Neither AC lines are getting cold / warm or its not sweating. I dont see the AC fan kicking on everytime I activate the AC. I did see it run it just doest kick on everytime I activate the AC

Any ideas from here?

tech2

the fan should be running on high when the ac is on...if not the system will quickly overpressure and the high pressure cut out will shut off the compressor. its hard to advise without knowing system pressures.

kevinkpk

You need to put gauges on it. If the clutch is engaging, and your not feeling any temp changes in the lines, you have an issue with the compressor.

ddemier7

Again the AC fan is not comming on when AC is engaged but compressor kicks on.

I have noticed when the heater is on, I feel passangers side vents are hotter than the drivers side.

Is this a blend door issue?

tech2

even if it was...the lines should be hot and cold. until you figure that out the door position is irrelevant. you won't get cold air out of a system that can't turn the ac tubes cold.

ddemier7

Dang it... you think I got a bad compressor?

Guage read out would tell me all that? Not sure im not a AC technician.

Thanks for explaining

oilcanhenry

You need to hook up an A/C gauge set and see what the pressures are, IMO. And I trained as an auto A/C technician, although as a profession, I am a professional rig driver. I've worked on many A/C systems both the old R-12 and R-134-A systems. All you are doing now is playing a guessing game. We need some real numbers to work with here. What Tech2 said holds and he _is_ a full-time professional automotive technician.

tech2

what he said.

maybe the compressor is bad maybe not....high and low side pressures might indicate where the problem is. I don't know what your system is doing bc I can't see what's happening with the pressures.


These are the only things a shop can do to diagnose an ac problem. (not a hvac distribution problem)
-confirm compressor operation....working
-check discharge and suction hose for hot/ cold....fail
-perform an ac performance test....fail
-confirm charge level...ok
-check for leaks...you say its ok
-check system pressures....???