Plastic insert into Bow up/down limit switch?
Hi. New to this site.
I have a 2003 CLK (W208) convertible.
I have an issue with the soft top. As a step by step........

I turn the soft top handle mechanism (above the reversing mirror) - windows and roll bar go down.
I pull the soft top switch in centre console - Bow unlocks and raises.
Tonneau cover does not respond. Switch flashes red.

I have manually stowed the soft top and tried to raise it automatically.
When pushing the switch in the centre console, the tonneau cover unlocks and raises.
The soft top lifts out and raises into the closed position.
The bow lifts, but the Tonneau cover does not go back down.
Again, red light on switch flashes.

As the motor, fuses, relays and hydraulics are all fine (each element of the procedure does work), my assessment is that the Bow Up/Down limit switch is not working properly.
It does not register when the bow has reached the fully open position.
On inspection, there is a plastic 'insert' that is grooved on the upper surface. (photo attached). This insert slides into what is presumably the limit switch. The other end is connected to the cylinder head.
As the bow lifts, the insert should travel further into the limit switch. as it does so, the groove moves the switch from one position to the next.
However, this insert is slightly damaged and does not travel all the way into the limit switch - hence the switch does not recognise the fully open state of the bow - and so the next part of the process (tonneau cover operation) does not happen.

I am no mechanic, but having read most of the forums and you tube clips, this is my assumption of how it works. I have not seen any photos or information about this bow up/down limit switch, what it looks like or how much it costs to replace.

Any information is greatly received.

 

The S84/15 'bow up/down' position switch must be activating properly for the controller to proceed to the next stage whenever opening or closing the power roof.

As shown below, the switch clips onto the left soft top bow up/down cylinder body. The switch has a sliding arm, that should be clipped onto the end of the cylinder's rod. When the rear bow is in the raised or lowered position, the switch properly actuates, and the controller will proceed with the next step of closing or opening the roof.




The S84/15 switch as been a fairly common problem, with either the switch becoming unfastened from the cylinder's body or it's pull in/out extending arm becoming unfastened from the end of the rod.

Usually DIY repairs have only required a method to refasten the switch to the cylinder body or rod.

Top Hydraulics has produced a video showing how to access the cylinder.


BTW, the picture you posted is only of the pull in/out actuating arm and not of the entire S84-15 switch. That arm appears to be bent as well as the fork that clips onto the rod may not be in good shape.

 

Thanks for the confirmation of what I suspected and supporting info.
You are right, the cylinder still works - the issue is with the plastic arm. Because this is dented, it does not retract into the cylinder properly.
If I manually push it in, the cylinder works.

Looks like £120 for a new cylinder, when I only need the plastic arm 🙄

 

Couple of suggestions.

Using a heat gun, you might be able to repair the issues with the current sliding extension section.

There are 2 rear bow up/down cylinders, so if you purchase a replacement, make sure it's the one that comes with the S84/15 switch attached.

You can also purchase just the switch itself and fasten it onto the existing cylinder (e.g. if it's not leaking).

 

Thanks for all the help.
Problem now solved.
Second hand Bow switch from a breakers yard - £25.
Only needed to replace the extending arm.


👍