I got a chance to remove my wiper assembly and do some testing. I ran the motor with out the arm that moves the wiper mechanism, and the hesitation is not in the mechanism.
Every once in a few turns, the motor would hesitate at the same location that it parks at and I noticed a spark through the hole shown by the arrow when this happens.
I removed this cover and this is what it looks like.
Has anyone had this happen? Should I wipe off the grease to see if I can find some kind of fault?