A/c inop

[houndog3]

I got a 97,5.7l z71. I went to turn the air on and i get nothing.And heres what i did.The compressor clutch does NOT engage.The ac light is on,fan works correct.I found the 10amp fuse under the hood and it checked fine and all the other fuses were fine there.I checked all the fuses in the cab aswell and they were fine.I unplugged the compressor and hot wired 12v to the compressor and the clutch did engage.then i started the it up with the compressor hot wired and she cranked out cold air.
does this system have a low refigerant bypass system?? if so where is it located at so i try to bypass it.thanks for any input

[brcidd]

Yes the cycling switch on the accumulator is the low pressure disable switch...but I would hesitate to tell you to replace it without measuring the refrigerant pressure-- the switch may be doing its job! It takes 47 psi pressure to enable the switch, if your system pressure is less, then you have experienced a massive loss of refrigerant. You need a gage set to measure pressure.

65% of mobile a/c failures are due to refrigerant leaks- so yours maybe low, and still had enough in it to make you feel it is cooling.

Number one leak location on your truck is the underbelly of the compressor-- is it oily/greasy? If so, that's probably the leak location.