How to Troubleshoot a Central Air Conditioner Compressor

Check your thermostat settings. If you've accidentally turned the unit off or set it to the wrong temperature, it might not be working properly because of these settings. Fix this before attempting to do any other type of troubleshooting.

Check the breaker box. If your compressor blew a fuse so that it's no longer getting any power, reset the fuse, and wait to see if the problem reoccurs. If the compressor trips the circuit breaker again, contact an electrician to investigate the cause of the electrical problem.

Turn off the power to the compressor unit before attempting any further troubleshooting. Do this by flipping the switch in the breaker box marked "Compressor."

Remove the compressor cover -- you will probably need to unscrew this. Examine the wires in the fan motor, looking for anything that is cut, burnt or charred. You may need the electrician to replace wires if they are damaged.

Examine the condenser fan, motor and coils for dirt or debris. If there's debris built up on any of these parts, wipe them down with a damp cloth, and dry them with another cloth.

Rotate the condenser fan with your hand. If it doesn't turn, something's wrong with the fan, and you'll have to get it replaced.

Put the compressor cover back on the unit, and turn the power back on. If the unit still fails to run properly, contact your service technician.