Condenser fan motors (CFM) are constantly exposed to all types of weather, which means they frequently need replacing. CFM are designed to utilize fan fins to cool hot refrigerant gases to keep your AC system cool. When CFM no longer functioning properly, they may not work at all, or it may blow warm air instead of the vital cool air needed to run the AC properly. A malfunctioning motor can cause the AC to overheat and fail entirely. These tips can be helpful for troubleshooting and replacing a condenser fan motor.
To determine if the motor has gone bad, supply power to the AC and watch the condenser. Within about 20 minutes, the fan should activate. If it doesn’t, it’s probably not working properly. To test whether it’s functioning, insert a stick into the blades of the fan and push gently. If the blades fail to spin, it is likely the bearings are shot, and you’ll need a new CFM.
In addition, you should check the breaker box to make sure the breaker hasn’t tripped and the AC is still receiving power. It is also possible that a contactor has gone bad, which can prevent the CFM from running. If the contactor shows high resistance when tested using a power meter, it may need replacing.
Besides the contactor, you should also test the capacitor, which provides the torque needed for the CFM to spin the fan. If either one of these parts tests bad, they’ll need replacing before assuming the CFM needs replacing.
Steps for Replacing CFM
Before attempting any repairs to the AC, make absolutely sure there is no power running to the unit. Flip the circuit breaker off, and double check there is no power at the AC unit with your meter.
Accessing the Motor
The CFM is located deep inside the AC unit. To get to it, you must first remove the outer casing or grill from the unit. Use a standard screw driver for removing the screws on the casing.
Remove screws from the fan and set it aside, so it will be easier for you to get to the wiring and the CFM.
It’s is helpful to take pictures of the existing wiring, and make a few notes about the colors of the wire and where they are attached. Your replacement motor may come with a handy schematic of the wiring. Disconnect the wires from the CFM.
Note position of the CFM and which direction your fan blades are facing before installing another motor. Unscrew any screws on the CFM that are attached to a small brace, which keeps the motor secured in place. Lift the motor out and slide the new one in. Attach it to the brace. Attach the wiring to the replacement motor.
Verify the replacement motor is working by turning the power on. Do not attach the fan during this test to prevent injury.
Completing the Installation
Reattach the fan. Place the casing on the AC and tighten down the screws.
Norris Air strives to provide helpful cooling and heating information to everyone living in the Mesa and Phoenix communities. If you would feel more comfortable using our professional services to make AC repairs, please contact our East Valley office at 480-832-3330 or our West Valley location at 602-595-3115 for assistance. You can also visit us online.