Just had the HVAC serviced (inspected) by firm that tightened loose wires outside, checked outside unit and inside blower, noting only slight dirt buildup on blower. Unit ran fine during tests. Next day, 2001 York diamond 80 HVAC blower fan stops after 20 seconds in the on position (not in heating/cooling).

Have volt meter, can I use it to test... something?

I want to replace any part that I can determine if defective. Need help determining what's failing.

Thanks,

keggers

Will it run on the heat cycle?

On the control board you will find a cool wire a heat wire and 2 park wires the fan motor should have a black probably on cool, a blue probably on park, and a red most likely on heat. It will also have a white going to a nuetral. Take off the cool wire and the nutral wire and turn your stat to fan on check for 120 volts between these two terminals. If yes the plug the wires back on. If fan does not start you can spin it by hand to see if it will run. If yes then you may need a new start capacitor. If no turn the power of and feel the motor. It may be off inturnal overlaod