A/C fan won't run on high
Working fine on low. When I switch to high, it hums like it is trying, but it won't start. Could it be insufficient power from the park?
Forum Discussion
If you are positive it is the fan motor humming and not the compressor, go on top and gently touch the fan motor case. After 5 minutes of humming a defective hi fan speed winding will cause the case to be hot enough to burn you. That means the fan motor is bad. A defective tstat will not cause a fan motor to hum and not run. The odds are the hi speed fan wire is off the Roof AC control board if the hum is the compressor and not the fan motor. It could also be AT the wall tstat but rare if it worked previously. Open the roof AC filter cover and you will see the tstat wires to the control board, just look and see if one spade terminal is not connected. Doug
