If you notice your AC condenser running erratically or starting up and shutting down right away, the problem might be with the condenser fan. The fan blows hot air out of the condenser so the parts and refrigerant cool down. If the fan doesn't operate properly, the parts in the condenser might overheat and shut down automatically. Even worse, the compressor might be damaged due to heat and strain.
A condenser fan problem needs to be fixed as soon as possible. Here's an overview of how an AC technician can test the motor for problems and replace the motor if necessary.
Narrow Down The Problem
Just because the condenser fan isn't working, that doesn't mean the motor is bad. The technician may test other components and even check the fan blades to see if there's a problem other than the motor. The capacitor and contactor can be checked by taking off the service panel. Since they're easy to reach, the technician may check them first.
The technician might trace the power from where the electricity enters the condenser and goes through the capacitor to the motor. They can use a multimeter to make sure the parts are getting enough power and passing it along to the fan.
Check The Fan Motor
If the electronic parts that assist the motor and the fan blade are functioning normally, the air conditioning technician will probably test the fan motor next. The motor is right under the grille on top of the condenser and right above the fan blade. The motor is held down with the blade, screws, and wiring. The technician has to remove the grille to reach the motor to test it with a multimeter to see if the motor is shorted out. If so, the motor has to be replaced.
Replace The Motor
The motor is fairly easy to take off and replace as long as it isn't stuck in place. Once the blade is out of the way, the motor can be pulled off and replaced with a new one. The technician has to be careful to match the motor to the blade and put the blade back on in the same position so the fan spins in the same direction as before.
Once the new motor is on and the wiring attached, the air conditioning technician can watch the condenser go through a few cycles of cooling to make sure there is no more short cycling and that replacing the motor fixed your air conditioning problem.
It can be difficult to pick up on problems with the condenser since it's outside and you may not be close to it very often. If your AC isn't keeping you cool or if you notice odd sounds or unusual behavior, go outside and check your condenser or call an air conditioning repair service for help before the compressor is damaged.