I'm having the same issue with the driver side rear window. I think it's a faulty ground.
FYI, carry another 12V source. I have one of those booster start packs I keep in the trunk. Pull the switch, the pins on opposite sides of the switch control up and down and go directly to the window motor. Attach the power +/- to opposite side holes. One way is up, reverse connections for down. If it works, motor is good. It's also easier than pulling the door panel, regulator, etc. No 2x4 needed if motor good. You could also do this with a lighter, power cord. Built in + and -. I use small alligator clips clipped into the holes.
Charles