Mechanics

AC PROBLEM

2005 Chevrolet Impala • 100,000 miles

2005 impala ac problem.
2005 impala 3.4l ac will not blow cold air. I checked pressure and was 0 when I hooked up r134a pressure was high, with out putting any of the r134a in the system. The compressor would cycle on and off ever 3 to 5 seconds. I jumpered the relay to add the r134a. The system took about 1oz and the compressor relief valve blew off the r134a since the pressure was to high. Any Ideas?
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9445ryan
July 19, 2012.



Iam really confused here said the pressure was zero then you said it was high when hooking the r134 up?How does that work?Also what were the high and low pressure readings at idle?Does the fan work to cool the condensor?

Saturntech9
Jul 19, 2012.
Yes the fan works, when I first checked the pressure was 0 the gage must not have been installed correctly. When I went to add the r134a the gage I had inline with the coolant read in the red (danger) area on my gage, not sure on what the actual reading was with out looking at the gage.

Tiny
9445ryan
Jul 19, 2012.
Your lucky you didnt blow your hand or face off bypassing the high/low safety switch then try to charge it while the gauge was in the red. Just so know if you get enough pressure in one of those diy charge cans then can go off like a hand gernand. So please dont ever bypass a high/low safety switch ever again or any other safety device. The reason the blow off valve blew was because you bypassed the high/low safety switch and too much pressure was built. So your going to have to replace the blow off valve thats a given. But before you do that I would try to read the high and low pressures?Whats going to happening though most likely is the pressures will rise and the compressor will cycle.I need to know what the high and low pressures go up to before the ac compressor cycles?You will need a actual ac gauge set to read the pressures. Not the low side diyer low pressure gauge/charge hose. If your going to diagnose this problem yourself. Otherwise you will have to take it to a shop.

Saturntech9
Jul 19, 2012.