I thought my motor was bad, it wouldn't budge the wipers. After some poking around, I discovered the problem was my pump. The arm that contacts the "star wheel" to drive the piston had rusted in place, causing the motor to stall (the arm appears to rest on the star wheel and "float" until the pump solenoid is actuated). A bit of penetrating oil and some gentle persuasion got it all freed-up. Not to say the old motor couldn't use a freshening-up, but it is functional again. Thought I'd share my experience, those motors aren't cheap to have rebuilt.
