power window doesnt work

On my 1989 Ford E350 van I had a periodic problem with the passenger window that would quit working but always in the up or closed position. Tearing apart the door and pulling the motor and window regulator would always seem to make it work again. I could never find any electrical issues with the switches or connections. One day I realized that since the window always failed in the closed position, I checked the window regulator and found that the gear on the motor had run all the way to the end of the gear and was jammed in that position until I either pounded on the door panel or took the motor off of the regulator. Sooo, I figured I'd grind another tooth onto the regulator. No go. Metal was way too hard. Then I decided that the problem had to be that the feltlike window moulding at the top of the window opening was compressed by the force of the window glass and allowing the motor gear to advance too far and jamming the gears.There is no switch to shut off the upward motion of the motor motor Solution? I peeled the top felt moulding down and stuffed a strip of rubber from a heater hose(any material to space out the felt moulding will do) and that was years ago. The window worked perfectly for years after that until I sold the rv.