How do you diagnose a failing compressor?
5 Symptoms of AC Compressor Failure
- The compressor doesn’t turn on at all.
- The system is blowing warm air.
- The system keeps tripping the circuit breaker.
- The outside unit shakes when it starts up.
- The outside condensing unit is making strange noises.
Is there a fuse for the air compressor?
Some air compressors have reset switches while others will have in-line fuses that need to be checked. To find them follow the line of power from the air compressor back to the outlet. If you find a blown fuse or tripped breaker go ahead and either replace the fuse or reset the breaker.
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.
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.
How is the compressor clutch relay turned on and off?
In some vehicles the compressor clutch relay is turned on and off by the low pressure switch and the evaporator temperature sensor. In a computer controlled system, the compressor clutch relay is grounded by the computer. If the fuse is good, disconnect the electrical connector from the compressor clutch coil.
What happens if you run a compressor with no oil?
At that point you’re running the compressor with little to no oil. You may get it to accept a charge, but you may have already damaged the compressor before the system reaches full charge. NEVER try to bypass the low pressure switch. Doing so will force the compressor to run with inadequate oil and can destroy the compressor.