So, the rear wiper on our 91 940SE wagon has been a little hinkey ever since we got it. Tended to blow the fuse (you know, the one that also powers the Climate Control?) if you shut it off too far from park position or used the intermittant setting. I think this was a bad ground due to the mounting bolts being a bit loose, though we haven't made final ruling on that.
Recently our two-year-old son decided to use the wiper arm to pull himself up onto the bumper. This relocated the arm to point straight down. I did manage to figure out how to get it to the correct park position and it seems to work ok BUT - once it tries to park, the motor does a stuttering stop/start routine across the window. Even does this when the wiper is pulled away from the glass, so it's not just dragging.
I checked the shaft that goes through the window - per the FAQ, but it is clean and well lubed, so no binding there.
Took the arm off of the motor so it could run by itself - still stutters.
I'm left to believe there are perhaps dirty or worn contacts in the motor. Is is possible to get the motor apart without destroying it? If so, has anyone managed to put one back together and have it work better than before?

Thanks,
Ben