Automotive Air Conditioning Information Forum

Delphi compressor on a 96 GMC Sierra 1500. I have a 1996 GMC Sierra 1500 4.3L V6 A/T (std cab), that my wife received from her uncle's estate. Sometime before he passed away, he had mentioned to her that the A/C "just stopped working one day". I am preparing to set about debugging the problem and I've come here to ask some questions regarding the compressor on the system. After wiping away the dirt on the label, I find that it's a Delphi SAE J639, however the "Part" potion of the label is not completely readable. It appears to be: (something) 587 or (something) 527. On the rear of the compressor, there is a circular 2-pin electrical connector which currently does have a 2-pin female connector wire attached to it. Delphi's web site says that their model CS0120 is the proper compressor for this model vehicle. However, the Delphi CS0120 has no such 2-pin circular electrical connector fitting on the rear of the compressor. We do not know if the current A/C system was a factory-installed system or a 3rd-party aftermarket installation. All I know at this point is that the electrical clutch will not engage, so for all I know right now, the compressor itself may or may not be serviceable. I was just trying to run down available parts and prices in case I may need them as I get further into the process of diagnosing the system. Any information you might have on a suitable potential compressor replacement would be greatly appreciated. Many thanks in advance.

The switch on the back of the compressor is used on some models, for various tasks.

If there is no connector nearby for the switch, it is just being used to plug the hole in the compressor. If there IS a mating connector nearby, re-install it.

Replacement compressors have the port, but there is a solid plug installed. If you need the switch for your system, you swap the plug for the switch from your old compressor.

There are a few reasons an old system may not work. Most often it is simply so low on charge the low pressure cutout is keeping the compressor from starting.

Have the system recovered & recharged to factory spec with a little dye & see if it runs.