Here's another stumper for you electronics guys. Just put together this motor, and during testing it runs great in forward, but just hums in reverse. It spins freely in both directions, and the E unit worked perfectly when it was tested separately. I installed new brushes with no improvement. I did notice that while running in forward, the E unit coil was getting unusually hot.
Just can't figure out why it runs so good in one direction, but not the other. So I need you electronics pros to bail me out again --- Please.