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.

Things You Will Need

  • Phillips screwdriver
  • Multimeter

About the Author

Michael Wallace has been a freelance copywriter and journalist since 2003. He served in the U.S. Navy and attended the Academy of Art University in San Francisco. Specializing in writing technical articles, Wallace has contributed to city publications such as "San Diego City Beat."