Auto Air Conditioning & Heater Repair: 1999 sunfire airconditioner problem, low pressure gauge, exact diagnosis

Question
my 1999 pontiac sunfire's air condioner works good when i am on the road. but when i am setting at a light or parked in the garage it blows warm air. i thought it to be low on freon. so i bought some freon and the low pressure gauge to add some. but my low side pressure is at 70 when the compressure does kick in and 120 when it kicks out.
my air has never been worked on pryor and this problem just started in the last 2 months.
can you help a guy in good old hot florida ?
thanks in advance larry

Answer
Fisr thing is to have to much freon in it. Bleed out what you put in before you blow a hose. the LOW side should ONLY be about 40 lbs when the compressor is running.

You most likely have a restriction in the orfice tube/expansion valve or your cooling fan is NOT operating correctly and is NOT cooling the A/C condensor.

You need to have a professional A/C facility make this repair as they will have to install a set of A/C gages on the system to make an EXACT diagnosis. Then the system has to be drained, evacuated and recharged with the EXACT amount of freon and refrigerant oil if necessary.




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