Let's say.. I've had a few older cars and when one door goes dead having a mechanic buddy with years of experience paid off. Your description seemed to fit too well. Glad you've located it.

A couple of ways to fix it is to disconnect everything in the door and pull some of the wiring back so you have some play to work on it in the door jamb. It's a pain in the buns area to fix stuff in...but it's not the worst there is.