1999 E320 sunroof problem
 

I'm a new user to this forum. I encountered a problem with my '99 E320 sunroof this past weekend. It continued to open and close without me touching the switch. I got it stopped at the open position, but I still can hear "clicking" sound. Later I had to pull the fuse to stop the clicking and closed it manually. What could be the problem? Thank you in advance for your advice/suggestion.

The sunroof cables are guided by small plastic tabs.
The original tabs were a bit TOO small & allowed the cables to wear & pop-out.

MB redesigned that part & made them longer.

Most likely that is your issue.

Thanks. I will explore if it is indeed the problem.

You didn't state if the sunroof opened & closed fully without binding. If the sunroof opened and closed smoothly then I would suspect a defective sunroof switch. If the sunroof started to bind when attempting to open or close then most likely you need new sunroof cables and updated guides.

1999 E320 sunroof
 

Southern, it did close and open smoothly but just won't stop.

I would try to re-sync the sunroof switch. With the sunroof in the vent position (closed with the rear of the sunroof up) push up on the sunroof switch for 5-6 seconds with the key in position 2.

Does the sunroof stop moving if you release the switch?

E320 Sunroof
 

in the latest incident sunroof woud close and open continuously with no response to the switch. when it stopped I can still hear the switch clicking. I had it de-energized now.

You need to get it scaned for trouble codes. The sunroof motor should be controlled by N10-1, called either a SAM or CCM depending on the year, which sits in the module box under the hood. It is controlled by the switch over the CAN bus; not a direct connection.

The scanner must be SDS or similar. The OBD-II port under the dash will not suffice.