brendon9

my a/c compressor will notengage on my 01 grand am. all fuses are good,
it is full of freon. can not figure out.
don

rgclark

Probably the pressure switch or the compressor clutch. I's check the pressure switch first. Simply unplug it from the accumulator and short between the terminals. If the compressor starts thats your problem.

MT-2500

Do not jump it if it has a pressure sensor.
You can blow the controlers on it by jumping.
What engine? automatic air controls?
If the compressor does not turn on how do you know it is full of freon.
You almost need a body/engine capable scanner to ckeck for codes and read out air cond controls and pressure sensors.
Any codes or check engine lights?
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

brendon9

I had guages on it the pressure was fine. it has manual a/c. 3400 engine

brendon9

I have not checked codes

MT-2500

What was the low and high side pressure reading at idle and at 2000 rpm with compresser running?
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

MT-2500

Get codes and if any post back and post back all pressure readings low and high and static pressure with outside air tempt.
MT

__________________
Remember proper testing gives us the answer to many problems.
MT

brendon9

i have 90 psi on the low and high but the compressor will not engage.

MT-2500

Just 90lbs on low side without compresser running does not tell us much.
To check for proper freon level you need to jump the compresser at relay or compresser do not jump at the 3 wire pressure switch {it is not a jumpable switch}and get a low and high side reading.
The pressure sensor will shut down air if freon is low or pressure is low or high.
To test the air cond system you will need a scanner.
it is computer controled.
I would get codes first and make sure it is full of freon.
I can send you a pdf on the test. BUT YOU WILL NEED A GOOD SCANNER TO RUN THEM.
If you want the 3 page long test in a pdf e mail me at crunch@troublecodes.net
MT

__________________
Remember proper testing gives us the answer to many problems.
MT