On Monday, June 29, 2015 at 11:08:32 AM UTC-7, wrote:

I thought these were induction motors. I didn't think about brushes.

Usually, the dishwasher motor runs forward to agitate and spray inside the
box, then the same motor runs backward to empty the water out. So, they
usually are reversed by swapping the brush connections.
Examine the motor carefully: if it gets wet, that can cause your difficulties
(and it would mean a seal needs replacement).