2002 Chevrolet Cavalier AC system

VALERIESMITH2792

MEMBER
2002 CHEVROLET CAVALIER
148,748 MILES

Yes I just resently put a brand new ac compressor, orifice tube, and dryer put the right amout of oil in ac compressor and filled with free on. My ac compressor will not kicl on unless I take the relay out and jump the compressor with a wire I thought it was the relay but my fuel pump relay is the same so I switched them and still did not work so I no its not the relay so I thought it was my ac switch on the inside so I replaced it and still same problem ac compressor will not kick on someone told me it could be the low pressure switch but I can not find one on my vehicle I've call an auto parts store and they tried looking it up and they can't find anything that says my vehicle has one. Plz if u could help me figure this out I just spent $400 trying to fix the ac and still not working we even blew all the lines out to make sure they wasn't cloged up.

Friday, September 13th, 2013 AT 8:00 PM

3 Replies

TY ANDERSON

MECHANIC
719 POSTS

Did you place the a/c system in a vacuum before charging with Freon? The pressure switch is located on the passenger from corner of the engine compartment on the a/c pipe. The pressure sensor has three wires running to it a grey wire, black wire and red with black stripe wire. Talk to you soon, TY

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Saturday, September 14th, 2013 AT 12:54 AM

VALERIESMITH2792

MEMBER
2 POSTS

I don't understand the thing about the vacuum but the pressure sensor we just replaced because it was broke. But still nothing we filled ac with the right amount of free on the gage said full now its a week later and there is no pressure at all like all the free on is gone and we can't find a leak anywhere.

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Sunday, September 15th, 2013 AT 10:35 PM

TY ANDERSON

MECHANIC
719 POSTS

Placing the a/c system under a vacuum causes all the air and moisture to get pulled out the system. When you pressurized the system with air already in it cause less Freon to enter and reduces cooling efficiency or at times not at all. This step can not be skipped.
It looks like you got a leak. Place the system under a vacuum with the a/c manifold gauges connected and after placing the a/c system under vacuum for 15mins shut off vacuum pump and let the system sit for another 15mins observe gauge reading it shouldn't drop if there is no leaks.
To check for leaks pressurize the a/c system with Freon then make a soapy solution with dish soap and water and apply around all joints and fittings even the service ports with a large brush. The condenser can get damaged by road debri like rocks hitting the condenser, so check there also.

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Monday, September 16th, 2013 AT 5:31 PM