Corroded wire, that's it!
Oh man, I've been dealing with electrical issues in my driver door for a while now, 2002 Jetta TDI Wagon.Thanks for your posts here!!! It's not the motor, it's not the switch, it's not the window assembly, it's corrosion!
Now I'm thinking this is all stemming from the notorious sunroof leak - water has spilled into the column where tons of wires run through. I had to pull off the panels under the steering wheel, pull up the left foot rest, and the panel covering the hood release. The aforementioned red (and white) wire was all corroded out, in the bottom of 3 assemblies.
Now just need to do a little electrical rehab, and hopefully will be good to go! Thanks for everyone's help!!!