What to do if your AC compressor relay is not grounding?
What to do if your AC compressor relay is not grounding?
But before splashing $100 on a replacement PCM you better be DARM sure the relay control ground wire is making contact with the above mentioned pin on the PCM. You can always use a meter to check if the PCM is working. Just connect one probe of the meter to the battery positive voltage and the other to pin 27 of the PCM.
Why is my a / C compressor not turning on?
When it senses that it’s cold, it turns off the compressor. Otherwise, the system would freeze. Well, sometimes these sensors short out and will not allow compressor operation.
How does the PCM control the AC compressor relay?
Also whit the switches closed (i.e. pressure OK) the PCM controls the relay via pin 27, closing the relay contacts (thus engaging the A/C clutch) when command received as long as the engine is in the proper RPM range.
Where is the relay on an AC compressor?
Basically when applying + to C3 (from the Cruise Fuse thorough the serially connected pressure switches) and (-) to the D1 pin (from pin 27 on C1 connector of the PCM – software algorithm) the relay closes the contact between pin D3 (from the A/C fuse – ORN wire) and pin C1 (to the A/C Clutch – DK GRN/WHT wire) engaging the compressor.
What causes an AC compressor to not engage?
If the clutch doesn’t engage, the problem could be a blown fuse, an open in the wire to the clutch coil, a bad clutch coil, a poor ground, or a low pressure lockout. AC compressor clutches receive power in a number of ways. They can activate through a relay that’s energized directly by a proper condition of the low and high pressure switches.
But before splashing $100 on a replacement PCM you better be DARM sure the relay control ground wire is making contact with the above mentioned pin on the PCM. You can always use a meter to check if the PCM is working. Just connect one probe of the meter to the battery positive voltage and the other to pin 27 of the PCM.
What should I do if my compressor clutch is not working?
If you’re not getting battery voltage, pull the compressor clutch relay and check for power and ground on the relay control coil terminals in the socket. Wiring varies by make, model, and year. Some car makers trigger the relay control coil ground through the PCM or ECM.
Also whit the switches closed (i.e. pressure OK) the PCM controls the relay via pin 27, closing the relay contacts (thus engaging the A/C clutch) when command received as long as the engine is in the proper RPM range.
