[alpac]

The top on my 92 SL has been working wonderfully with no problem since I finished replacing all the cylinders over a year ago. I used my SL several times a week and drive open as often as I can. This morning though I tried to open the top and it did not work, the red button kept blinking but nothing else. The first thing I checked was the level of hydraulic fluid in the pump reservoir and it was at the top level, same as when I refilled it more than a year ago. I still looked at potential leak from any of the cylinder but no leak anywhere. I opened the top manually and tried to close it automatically to no avail. I then closed it manually and tried to open it automatically but still not working. I used the car last wednesday and the top worked perfectly. The last person to use the car was my wife on Thursday but she did not open the top. The only thing she said she did was to lock the glove boxes using the lock key lock on the dash. Not sure what she did that but I dont see any possible link between using the lock on the dash and the top not functionning anymore. So now I am wondering what should be my next move to figure out where the problem is coming from. Any suggestion?
Thanks

 

[RKH]

Any electrical problem, first thing is to check fuse

 

[Ruindr]

+1 on checking all related fuses, both up front and in the trunk.

Did you have your engine running to ensure sufficient voltage? Gear in park?

(If yes to Q1, disregard the second Q)

 

[alpac]

I checked and cleaned the 2 fuses in the trunc related to the soft top which are #3 and #7. I dont see any fuse under the hood that are soft top related. The battery is good, the car crunks real good. The soft top is on right now. If I press the soft top button toward closing I can hear the rear locks making some noise. If I pull the soft top button to open it the red button just blocks but no noise nothing. Both windows operate properly when using the window switches.

 

[Richard F]

Worth reading the codes as well.

 

[Ruindr]

I dont see any fuse under the hood that are soft top related.

On my 98 fuse #19 in the engine compartment is for the soft top control as well. But that could be different on yours of course. I'm dealing with a closing issue myself at the moment (see recent posting), but it seems different from yours and also different MY.

 

[RKH]

How about #9 fuse in the trunk ?
Have you check the Rollbar ? it needs to be functional for the top controller to operate.

Your car is '92, I would check ALL fuses. Measure them (or swap like valued fuses around), not just look at them

 

[alpac]

Ok i will check all the fuses. The rollbar works fine.

 

[alpac]

I took out and checked every single fuse and they are all fine. Everything works fine on the car except the top. Windows, roll bar, etc.. everything works. As I said previously there is no leak leak and the hydraulic fluid is at the high mark. For some reason the soft top logic thinks that something is not quite right and does not enable the top to work.

 

[RKH]

Well, you have checked the easy stuffs, next step is to scan for codes.
Could be some of the micro-switches out of adjustment and proper scanner will point you to it.

 

[bobterry99]

This morning though I tried to open the top and it did not work, the red button kept blinking but nothing else.

It is not unlikely that a fault code is stored in the controller and operation is impossible without first reading and erasing the code. I suggest you read and erase all codes from the top controller following the procedure explained here. You need nothing more than a short wire or paper clip to read codes from socket #10. Then try the top -- if it still does not work, read codes again and reply back with your findings.

 

[alpac]

Well, I decided I would give up for the day on that soft top issue. One of my stop light was burned so I took the SL for a ride and went to Autozone to buy a new bulb. Once back home I tried the top again without any hope but guess what! it worked perfectly. I did several iterations of opening and closing and it works all the time now. Go figure ... May be it was one of the fuses after all that did not make good enough contact until i cleaned it and the car just needed to be driven. I am really not sure what the issue was but it is working now. My SL must have a mind of its own as it does that type of things every so often. Something that used to work stopped working and then for no reason works again. The last one before the top problem was the clock that stopped working back 3 years ago. 2 months ago it started working again for no obvious reason and has been perfectly on time since.
Anyway thanks for all the advises as usual. Now I can focus on fixing my wife's CLK soft top that developed a leak a week ago. At least I know what the problem is and which one of the cylinders leaks as well as how to fix it. Got good training with my SL After replacing all of my SL's hydraulic cylinders here I go again with my wife's car. You have got to love these convertible Benz's

 

[alpac]

It is not unlikely that a fault code is stored in the controller and operation is impossible without first reading and erasing the code. I suggest you read and erase all codes from the top controller following the procedure explained here. You need nothing more than a short wire or paper clip to read codes from socket #10. Then try the top -- if it still does not work, read codes again and reply back with your findings.

Thanks a lot for that information on reading and clearing the codes.

 

[isthenew]

Glad you got it working!

I was gonna chime in on the fuses for alarm system and power windows. But I now have a question, because the windows on the earliest cars didn't drop when opening the doors. So would these fuses not apply to those cars (i.e. 1992)?

And I'd check the sensor where the soft-top hits the windshield. I'd think that shifted and may be loose before I'd think a fuse finally started working right. And I'm a huge fan of replacing all the fuses first!!!

 

[RKH]

Even without the window-drop feature in earlier cars, the top controller WILL lower the windows and rollbar all the way down before operating the top.

 

[alpac]

Even without the window-drop feature in earlier cars, the top controller WILL lower the windows and rollbar all the way down before operating the top.

Correct and if the windows do not work, like for example if the window fuses are blown, then the top will not operate. I had that problem once

 

[isthenew]

Even without the window-drop feature in earlier cars, the top controller WILL lower the windows and rollbar all the way down before operating the top.

*smh* Stupid hurricane Irma got me to where I didn't even think of that....

So windows fuses need to be checked even in the oldest cars. How about the alarm?

 

[bobterry99]

On an early car if the top is in a home position (i.e., fully opened or closed) then it will initiate the automatic sequence provided the controller is powered by fuse #6 in the main fuse box and fuse #3 in the rear fuse box, and there are no internal fault codes blocking operation. Later in the sequence the window-lowered limit switches are checked and monitored for the sequence to continue. Naturally, if a window was not lowered when the sequence began, then its associated fuse in the rear box must be good in order for the top sequence to complete.