I've had this sunroof problem for awhile and am getting around to fixing it this summer. I've taken two sunroofs apart and interchanged the good pieces of each, removed all the broken plastic in the track, and lathered everything in plenty of grease.

Once plugged in and I turn the switch, everything sounds like it's moving properly. I don't hear any cracking or strain coming from the motor.

I had the window closed as much as possible by hand when I plugged in the switch itself. When I turn it, the window slides 3 inches and then moves back the opposite direction an inch or so. When I move it to vent, it only raises maybe half the way. I can get it to return to the closed position, but it's like the motor doesn't want to work long enough for it to work properly. The track it slides on to open seems to be pretty smooth and nothing in the way.

Any ideas?

 

Have you made sure the switch itself is good? If not, you may need to fix Or replace it.

 

I have this same issue. It opens when and closes back and is a pain to get it back closed all the way. I'm thinking maybe the contacts are dirty?

 

It's pretty common for the switch to go bad. I had my sunroof opening and closing on its own in my B5 at one point. Cleaning the switch made a difference for a while but it eventually died altogether and I replaced it.

 

Before plugging the switch in, I disconnected the circular connector and cleaned it with rubbing alcohol as a precaution to avoid this. I have an extra switch I'll try soon.