I just bought a 2001 Z06 and the A/C doesn't work. System was just charged up by the a car dealer and they said it worked fine. Shipped the car to me by carrier and it doesn't work. I put the A/C gauges on and it's charged properly,fans come on like they should, compressor comes on like it should but is building no pressure. Took the A/C compressor apart and everything looks mint. Put it all back together and recharged it again, same thing. The high and low pressure switches appear to be working properly everything else looks fine but the compressor isn't building any pressure/suction. I can't see why the compressor won't work, it looks like new. Anybody have any suggestions? Is it possible that it really does need a new compressor? Is there something else in the system that could cause a loss of pressure/suction and not be the compressor itself? I have no problem buying a new one I just don't understand why this one doesn't work. The external temp sensor seems to be stuck at 61 whether I heat it or cool it so I ordered a new one. The climate control display fades in and out sometimes but all the functions seem to work and is not flashing any codes.I don't know what else to do other than go and buy a new compressor but I'm still not sure that's the problem. Let me know your thoughts. Thanks

 

Could be your climate control module? might not be sending signals to the compressor, if it is flickering i would check it out first before buying a new compressor.

 

use the search..a bunch of AC threads on here one probably has the issue you are experiencing.....good luck

 

Quote: compressor comes on like it should but is building no pressure.
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Probably would help if you list the readings from the guages. You say NO pressure. Well if that is the case, then the compressor will not come on.

 

it has the a/c charge pressure in the system which allows the compressor to come on but the system doesnt seem to build more than a couple of pounds above that. The charge pressures are stable and not much change in them at all pointing to a bad compressor but if you had seen it all apart there is no reason why it shouldn't work. The pressure on the gauges is 70-80 on the low side and 100-120 on the high side and they don't move much at all wether the compressor is running or not.

 

The pressure on the gauges is 70-80 on the low side and 100-120 on the high side and they don't move much at all wether the compressor is running or not.
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If the compressor is not running, the Low side and the High side should be the same. Have you pulled the orrfice tube to inspect it?

 

no I haven't pulled out the oriface tube to look at it. I didn't think that it was going to be an issue because it didn't think there was any blockage issues and the compressor was clean and didn't think that there would be any metal in there

 

just pulled out the oriface tube, there is a small amount of metallic debri on it but nothing bad enough to plug it and not work properly.

 

Have you tried actually removing the outside air temp sensor?

Once the old sensor is removed, the HVAC defaults to 69* and will let the AC turn on.

GM Part # 10248414 is aprox. $10 from the dealer and just plugs in.

The sensor is located on the right (passenger) side of the car, on the outside of the frame rail in the very front by the headlight.

It is held onto the mounting hole on the frame by a plastic push-in clip.

Just pull the clip out of the hole on the frame, release the plug for the wire (the plug has a release clip, pry up on the clip and the plug will release).

Then just put in the new one and you will be in business - it takes a few minutes of driving for the sensor to start reading the outside temp - you have to be moving.


The sensors are either resistance temperature detectors (RTD's) or Thermistors. The resistance of the sensor changes with the temperature.
If you have any corrosion in any of the associated connectors it will increase the resistance that the climate controls is reading.
The resistance across the two sensor wires could be almost infinity,
in that case your display would read a low temp.

 

Hi, thanks for your reply, I have taken the sensor off and it makes no difference. The A/C sytem functions properly but does not build any pressure/suction when the compresssor is running. It does come on and stays running but is basically doind nothing. I found out today that all of the Corvettes run a V7 Compressor and have a pressure control valve built into the back of them and are known to be faulty and cause my symptoms. I took it out and cleaned it but made no difference. I would have just bought a new one for $35 dollars but there is no stock in town and it's a bit of work to get it out of there. I think I will probably just order a whole new compressor and be done with it even though I believe that the conrolt valve is the problem. Thanks

 

Is the compressor clutch by chance slipping?

 

So you have stated that the Compressor looks like it is new, is it? If it is new, is it possible that the compressor failed at some point and was replaced without replacing the accumulator? If you found metal in the orofice then maybe you have a blocked accumulator?

 

I don't think so because i'm not seeing any abnormal pressures anywhere in fact like I said the compressor is not making any pressure or suction. The clutch engages and isn't slipping, I think that i have narrowed it down to the pressure control valve in the back of the compressor or just a worn out compressor. A faulty Pressure Control Valve can and does cause the compressor to do the same thing (no pumping) I took it out today and got rid of some excess oil,cleaned it and reassembled everything, recharged system but no diffference. No one in town here has one in stock or else I would have replaced it for the $34 dollars. I think I'm going to order a new compressor,dryer,oriface tube and seal kit and just replace it all. After doing some more research this pressure control valve that I'm talking about is a common problem not only with the GM compressors but some imports as well running the v5 -v7 compressors. A lot of compressors have been changed over the years when all they probably needed was a new pressure control valve. They say that it is a 50/50 chance that this is the problem and it's the cheaper one to try first before replacing the compressor. Thanks for replying to my post