2003 GMC Sierra Compressor not going on.

  • 2003 GMC SIERRA
  • 69,000 MILES
So my truck's fan stopped blowing, I replaced the resistor, and the fan started to work but the compressor stopped going on (It worked fine before the fan blowing issue.) I did blow a fuse when working on the wiring, a 40A HVAC fuse, which I replaced, but the compressor still isn't going on. I checked all the fuses for the HVAC system and all look good.
At one point I was thinking that the parts dealer gave me the wrong resistor, possibly one for a heater only truck, and that this was why the compressor wasn't going on. I checked online though and it seems my resistor is the right one.
So now I just tested the A/C system low pressure switch by jumping the plug and the compressor still didn't kick on. According to what I've read if the compressor did not kick on then the compressor isn't getting power or has something else faulty with it. Is this correct? How exactly would I test if the power is getting to the compressor? There are two wires running to the compressor, a black and green. I assume I would check the volts running to the plug's green wire. Is this correct?
Do you
have the same problem?
Monday, July 2nd, 2012 AT 5:29 AM

1 Reply

Un plug the 2 wire @ the clutch Lupe a test light in line with the to wires and see if it lights. The green should get voltage when there is a request for ac. The black is a solid ground. Also try adding voltage and a ground to the to wires with it plunged in to see if it works that way
Was this
Monday, July 2nd, 2012 AT 10:57 AM

Please login or register to post a reply.

Recommended Guides