How to fix stuck electric sunroof on MkIII VW?

Question

The electrically-operated sunroof on my Mk3 (1995) VW Golf has trouble operating under its own power. When I push the button to open/close it, it moves a fraction of an inch and then gets stuck, with something in the circuit making an audible "click" noise. It is possible to open/close the sunroof all the way by pushing the button dozens of times in quick succession.

What's a good way to investigate / fix this? Does it just need some kind of lubrication, or is there a problem with the circuit? (The click noise makes me think that something is overloading, or ... something.)

Answer 1

There are really only two possibilities, or a combination of both. First, the motor may be failing. Over time, they get "tired" and will open and close sluggishly. Before your sunroof malfunctioned, did you notice it getting more sluggish over time? Opening, closing, or both?

The second possibility is a physical obstruction. The click you are hearing could be a misalignment of the track or debris. OR the circuit can be designed to trip if it encounters a certain amount of resistance to avoid doing any damage. Remove the interior panel (the one that slides into the headliner) to make sure thats not blocking movement. Next look to see if there are any areas you can clean and/or lubricate to see if this improves.