How to Diagnose a Split Phase Motor

Turn off the power to the motor from the breaker in your home or through the appliance itself. If you have a split-phase motor in a refrigerator, unplug the refrigerator.

Gain access to the motor. If the motor is inside your AC unit, remove the unit casing from the unit. If your motor is freestanding, then you already have a leg up on troubleshooting it.

Look over the motor to make sure that it is not burned out. Carbon buildup on the motor’s unit casing will show that it is burned. Check the motor’s stator to make sure that it’s not jammed. The stator is the shaft in the middle of the motor. This is the actual moving part of the motor. Turn the stator to unjam it from the motor.

Test the motor with a voltmeter to make sure that it has the proper voltage. Touch the voltmeter’s leads to the motor’s terminals to get a proper voltage reading. The voltage should be within a range of 10 percent more to 10 percent less of the motor's recommended voltage.

Reset the terminal switch on the side of the motor to make sure that it has not been tripped. Check over the wires connected to the motor. These are the power leads that give the motor power. Use a soldering iron to reconnect the wires if they have come off of the motor.