Soft top problem, 91SL

[Roger65]

This is my first post-great site here. I have a 500SL which I bought last August. The car is a dream come true, except for one thing.

The top on my 500SL will close fine automatically, but when I pull back on the switch to open, it pulls the top tighter against the body. It is as if the system does not realize that the top is closed. The top will close fine, but once the top is up, pulling the switch back or forward have the same result, I can hear the motor run and actually see the top being pulled against the windshield frame. I did a search on this site and it seems we have some good softtop gurus here, so I am hoping someone might have heard of this before.

Thanks,
Roger

[Eli (NJ)]

That's a little strange to me, but here's some hints anyway. The switch has a light in it that tells you what's happening. When you complete the process of lowering or raising the top and release the switch, if it stays lit then 1 of the locks is still open (the windshield header or boot locks). If it is flashing, then something went wrong during the process (usually electrical). I know this is not very much info, but see what you get first then post results.
Eli.

[chad500sl]

My 1990 500sl had the same problem. It was caused by a switch in the top compartment not being triggered. On my car there is a blue switch on the driver side, about a foot back from the roof pivot. It had a rubber washer the roof pushed on. Over the years this washer had developed a flat spot. I simply spun it to a new position. I figure I'll probably need to spin it again in another ten years. Hell I might even replace it then. Hope this helps.

[bobterry99]

You might consider checking for fault codes, as explained here:

Questions for techs on my SL, please read>>

and perorming diagnostics, if necessary, as explained here:

500sl Soft Top And Roll Bar

[Roger65]

Thanks for all of the replies. Chad- I hope my car is as simple to fix as yours was! I am going to try your idea this weekend. If not, then I hit the diagnostics.

[Roger65]

Chad, I took a look at my top mechanism today, especially looking for the switch you mentioned. I couldn't find anything that had a rubber washer. is it in the compartment beneath the tonneau, or accessed through the trunk? I did see a blue switch in the area about 4 inches behind the top pivot, but it just slides up and down, without a washer. What components are in the vicinity of that switch/ any help is appreciated.

Thanks
Roger

P.S, I had the car into the MB dealership last September, and they couldn't find any fault codes related to the top. My ads was bad at that time, so I opted to do that instead. The local independant MB guru gave up on the top, after an hour or so he decided he would not spend the time to diagnose it. You guys are my last hope!

[chad500sl]

The blue switch you mention was the problem on my car. This switch wasn't being pressed far enough, so the car thought the top was always up. My car had a little peg that stuck out from the top with a rubber washer / gromet around it. Spinning the washer caused the flat spot on the washer to be away from the blue switch. This gave the switch just enough more movement to work. Make sure the switch "clicks" when the top is down. On my car, the switch would sometimes not activate when the top was down. Pressing slightly on the top would cause a "click from the top.

Hope this helps,
Chad

[Roger65]

Update- problem solved!

Chad, it was the switch you mentioned, only I had the opposite problem, my switch would not pop up all the way when the top was raised. When raising the top, I now reach back and manually reset that switch by pushing up on it until I hear a click. My top has worked every time I have done this.

I have new switch on order, $40.85 from the MB dealer. Not bad.

I want to thank everyone that replied Chad, bobterry, Eli, you guys are the best! You probably saved me 500 bucks, as well as a helping of dealer grief trying to get this diagnosed.

Thanks again
Roger