Why does my a/c in my car squeal?

Question

When I turn on the a/c it makes a really loud squealing noise.The defroster does the same thing and it's not the belt because that is new and was just checked yesterday.So anybody know why it's doing this?Somebody told me it was my a/c clutch.If it is the clutch should I just but the whole a/c compressor?

Answer 1

If the belt was just changed and your sure that the belt is on tight enough and you say that the problem also occurs when you use the defrost it sounds like it may be the blower motor in side the vehicle. Turn the fan on without the A/C to see the problem is still there if not have the air compressor checked. If problem is there with fan on and no A/C it would be the blower motor in side the car. Good Luck!!

Answer 2

when the defroster is on THE A/C IS RUNNING.  feel the air and you'll see that it's cold air.

wonder if the unit needs compressor oil.

Answer 3

   There is a common factor in you problem. Your ac compressor comes on when you turn on your ac of coarse and it also comes on with your defroster. It would help to know what kind of car but ac systems are all very simular.

  To double check the belt, I take the garden hose with a spray nossle and give a quick shot of water right where the belt meets the pully. If the squeeling stops for a second then the belt is glazed over and needs replacement.

  I know you just changed the belt but if you run even a new belt loose it slips on the pullies, builds heat and glazes over.

  The other thing you can try is disconnecting the ac compressor pressure switch. This will turn off the compressor and if your squeel goes away and the above had no effect, then the compressor is bad.

  Do remember that when compressors go bad they usually deposite debrie into the system that MUST be flushed out or it will take out your new compressor.