I changed my capacitor a few months ago because my outside unit fan was slow to come on. I hooked everything back like I had found it and the fan would come on. It was very hot today and I noticed that my air conditioning wasn't getting the house cool. I weny outside and discovered that my outside fan was sucking air in instead of blowing. I went to the neighbors and my fan was turning the opposite direction. Whay is causing this?

Change the motor and replace the cap if different than the one you have.


Seems to happen for some unknown reason and the fix is replace the motor. The only reason I can think of is that the motor got magnetized for some reason like a surge. Would love to try to see if degausing coil would work.

I had the same thing. Try putting in a new capacitor corrected my problem

Outside Air Conditioner Unit: Fan Spinning in Reverse

Recently I replaced the contact relay and the capacitor (dual capacitor) on my 2.5 ton Payne outside unit. I thought that I wired everything on to the new capacitor correctly by following the wiring on the old capacitor. However, when turning on the unit, the fan on the outside unit spun counterclockwise. The unit was Sucking In Air rather than blowing it out, which is bad for the unit.

Solution: Originally on my unit the Brown Fan wire went to the Fan position on the old capacitor. The other Light Colored Yellow Fan wire went to the Common position on the old capacitor. However, wiring it the same way on the new capacitor reversed the rotation of the fan, thereby causing the unit to Suck In Air. By reversing the Fan Wires on the new capacitor, the fan spun clockwise and the air was blowing out of the unit. On the new capacitor the Light Colored Yellow Fan wire was this time connected to the Fan position of the new capacitor and the Brown Fan wire was connected to the Common position of the new capacitor.

Note: If your compressor has a delay in starting, you may want to consider adding a hard start capacitor. This has two Black wires that are wired to the Compressor position of the capacitor and the Common position of the capacitor. Wiring order does not matter.

Crabman

Crabman,
Some Outside fans have an extra pair of wires, when swapped, it will reverse direction.

If it didn't spin backwards before and no new motor has been put in, then the capacitor is bad and needs replaced.