The sunroof on my 1980 300sd w116 has stopped working all of a sudden. The first thing I did was check the fuse which was ok. I then took a battery and wired it directly to the sunroof motor. Sunroof opened just fine, I reversed the polarity and it closed just fine. This led me to believe the sunroof switch had gone bad so I bought a new one and intalled it today. However, still nothing. Anybody have any ideas as to what might be going on?

KJenkins,

I just had a similar problem. I too checked the fuse, then the switch. Instead of replacing, the switch, I disassembled and and cleaned the contacts. Still no results. Next, I checked the voltage at the sunroof motor while my spousal unit depressed the sunroof switch. If I remember correctly, the voltage was somewhere around 7-8 volts????

At this point, I went back to the fuse block and took the fuse out in order to check the voltage at that juncture. This is where I found the problem. While the fuse was intact, there was a small amount of corrosion at the fuse contact points. I brushed up the fuse and contacts and "wallah." It worked.

I hope it is this simple for you.