So after I rebuilt the heater box and got everything back together, my wipers didn't work. I thought I must have bumped something loose behind the dash, so I tore into it again. All of the wiring seemed to be O.K., as did the motor and switch itself (fumbled around with the multi-meter for a while).
We had a spare used motor on the shelf, so I hooked it up along with a ground wire since the motor wasn't attached to the windshield, and it worked fine. Hmmm. Hooked up a new ground wire to the existing motor and it worked again.
Guess those window hinges aren't the best ground.
Since pictures of a ground wire aren't all that exciting, and not wanting to get in trouble with Big Walton, here are a few gratuitous grandkid shots. In the first, Jonah is supervising my electrical work. The second is in HIS new Jeep, courtesy of Mr. & Mrs. Beep. It you look real close, you can see his head gasket is leaking. He's a real Jeeper, that one.