Passenger window won't move up
 

I got in my car today, and as soon as I started the car, the passenger window automatically rolled down and wouldn't roll up. I rolled all the windows up using the key in the door and the passenger went back up. I got back in and it rolled down again. Now, it won't roll up even when I use the key in the door. I don't know if it's the switch, motor or anything else.

P.S., It rained hard last night.

I had this problem more than once on my 1989 100 Quattro
I always got varying opinions as to what was wrong - motor, switches, even had a motor / regulator replaced, only to have the same problem again months later - it turned out to be bad /broken wiring in the harness passing through the pillars to the doors