PCM not sending ground to A/C compressor relay?
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PCM not sending ground to A/C compressor relay?
I put a brand new A/C system in my 98 Z28. While charging the system, the compressor would not kick on. I jumped the A/C compressor at the relay to take the charge. Pressures are dead on, good vacuum, no leaks, showing 41 degrees from the vents. The compressor will not kick on without jumping at the relay. Jumpering at the pressure sensor also did not turn on the compressor. I put a brand new relay... no good. I replaced the pressure sensor with a brand new AC Delco, no good. On the relay, we tested the 4 plugs for the relay. getting 12v to two plugs, a solid ground to one and not getting a solid ground to the other. I know the PCM sends the ground, my radio clock is working properly. I checked all of the wiring and pins on the PCM, all look good. I also checked and cleaned all grounds to block and body. Anyone got any ideas, please help.
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Update:
I chased all of the wiring from the pigtails to the PCM pins. Wiring is good. Pretty much narrowed it down to a faulty PCM. Gonna see if a reflash will work or if I have to replace it. I will update the results after.
I chased all of the wiring from the pigtails to the PCM pins. Wiring is good. Pretty much narrowed it down to a faulty PCM. Gonna see if a reflash will work or if I have to replace it. I will update the results after.
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Alright. Problem solved! It was the PCM. I ordered a used PCM from that madtuner guy. Had my VIN flashed in. Hooked the PCM up. This resolved all issues. A/C works properly, gas gauge works properly, and all is well.