Fan Motors

The Fan Motor is the driving force pushing air through the coils & ducts it is a vital part of the system. The fan motor gets its initial power from the start capacitor, and then switches to the Run capacitor after it gets up to speed.

Symptoms of a defective fan could include tripping the breaker, or not running on one, or all speed settings

Maintenance

The some fans need occasional lubrication

Troubleshooting

Continuity Test

• Turn the A/C breaker off

• The fan motor leads are White (neutral), Black (High), Yellow (Medium), & Red (Low). If your checking a 2 speed A/C, ignore the yellow wire.

• Set your Voltmeter to Ohms & measure resistance between the white wire, and each of the other wires (Black, Yellow, Red). If you don't have continuity between any of those wires & White that indicates an open circuit and the fan will need to be replaced.

• To check if your fan is grounded, check each wire for continuity to the Green/Yellow wire if you have continuity to ground on any of these wires the fan needs to be replaced

Running Amp Test

• Turn the A/C breaker ON.

• Set the fan to High

• Check the incoming voltage between the White wire, & Black wire at the selector switch to verify you have 120VAC on the circuit.

• Using the Amp Clamp on your Voltmeter check the amperage on the Black wire.

• If the incoming voltage is acceptable, and the amp draw is higher than specifications check for dirty filters, Dirty coils, if your motor requires lubrication, And the Run Capacitor.