My front wiper sputters when on intermediate speed. I pulled the wiper assembly and the motor looks fine (I pulled the case and checked the brushes and commutator) then ran it without the assembly and it worked fine. Then greased it all up and put it back together but the problem persists.

I suspect intermediate mode just issues a start pulse and relies on the self return mechanism for the wiper which is probably the probably the issue. Since the wiper returns to the stop position from low / high speed... I can't think of what it would be other than some controller issue.

Thoughts?