How to Check an Air Conditioning Compressor for a Short Circuit

The compressor in your air conditioner is a cylindrical component that compresses low-pressure air intake. This allows the unit to convert this low-pressure air into high-temperature, high-pressure air. Without a functional compressor, the AC unit won’t operate. That’s why it’s important to try and diagnose any problems that may arise. One potential problem is a short in the wiring of the compressor.

Step 1

Power off your air-conditioning unit and unplug it.

Step 2

Remove the screws on the back panel of the unit where the fan is.

Step 3

Remove the back panel. The compressor will be just above the fan on the inside of the unit. Notice the electrical wires running to the compressor.

Step 4

Plug the air conditioner unit in, and turn your multimeter on. Set the knob on the front of the multimeter to "V." This means it will read in volts.

Step 5

Touch the end of the red lead running from the multimeter to the circuit where it connects to the terminal on the compressor. Touch the black lead to a nonelectrical metal object to ground the multimeter.

Step 6

Wait for the multimeter to produce a reading. If it doesn't, there is likely short in the wiring and a technician will need to repair the problem.