SL/R129: Help needed soft top Controller replaced still issues
Thread Starter
Newbie
Joined: Nov 2024
Posts: 4
Likes: 2
Mercedes R129 SL320 1996
Help needed soft top Controller replaced still issues
Hi I am hoping that someone can help me troubleshoot and repair my 96 SL320.
I had 2 battery drains "Parasitic drain issue" and soft top and roll bar stopped working. After sending the controller to be repaired all seem to work but there was still roll bar lights and roof button light.
The controller was sent back additional repairs to it and a video showing it is working on another r129.
I decided to buy a second controller off eBay and the issue I am having is exactly the same with both controllers
On connecting the battery and opening a door window drops halfway,
- Window switches will not work,
- Roof button light red
- Rollbar will not work
- Buzzer sounds when driven
The soft top close cycle seems to be out of sync
The only way I can get the windows up is combination of roof button forward and hold window button until up.
I have read hours of post here by some knowledgeable people "Klaus Top Hydraulics and Bobterry" but can't seem to find anyone with similar issues.
Any help really appreciated
I had 2 battery drains "Parasitic drain issue" and soft top and roll bar stopped working. After sending the controller to be repaired all seem to work but there was still roll bar lights and roof button light.
The controller was sent back additional repairs to it and a video showing it is working on another r129.
I decided to buy a second controller off eBay and the issue I am having is exactly the same with both controllers
On connecting the battery and opening a door window drops halfway,
- Window switches will not work,
- Roof button light red
- Rollbar will not work
- Buzzer sounds when driven
The soft top close cycle seems to be out of sync
The only way I can get the windows up is combination of roof button forward and hold window button until up.
I have read hours of post here by some knowledgeable people "Klaus Top Hydraulics and Bobterry" but can't seem to find anyone with similar issues.
Any help really appreciated
Junior Member
Joined: Jul 2024
Posts: 34
Likes: 4
From: Colorado Springs, CO
1997 SL320, 1972 TR6, and 1981 Euro 230CE
Have you manually cycled the top up/down a time or two to get everything back in sync? If you manually put the top up and lock all the locks that should give you a basic starting point.
Has the soft top ever worked automatically under your ownership?
Has the soft top ever worked automatically under your ownership?
Thread Starter
Newbie
Joined: Nov 2024
Posts: 4
Likes: 2
Mercedes R129 SL320 1996
Hi Yes I have cycled soft top manually a few times prior to controller being repaired and after also. On one occasion I was unable to lock the rear bow locks as they were hydraulicly locked I had to make 2 loops of wire to hold them open to close bow.
The soft top was working fine since I got the car in 2018.
I purchased Xentry mb star C3 from china but is has a bad cable setup that will not read codes and In ireland its impossible to find someone with MB Star.
The soft top was working fine since I got the car in 2018.
I purchased Xentry mb star C3 from china but is has a bad cable setup that will not read codes and In ireland its impossible to find someone with MB Star.
Junior Member
Joined: Jul 2024
Posts: 34
Likes: 4
From: Colorado Springs, CO
1997 SL320, 1972 TR6, and 1981 Euro 230CE
So it appears that the parasitic drain events produced a low/dead battery and that is when the problems started. Did you replace the battery with a new one?
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
Thread Starter
Newbie
Joined: Nov 2024
Posts: 4
Likes: 2
Mercedes R129 SL320 1996
So it appears that the parasitic drain events produced a low/dead battery and that is when the problems started. Did you replace the battery with a new one?
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
The star is from aliexpress and it only reads the engine modules as it is has only 16 wires to each 38 pin socket lol.
I am trying to get a new 38 pin cable but all seem to come from china and have 16 wires. I contacted my local MB dealer and its unavailable to purchase.
I did try multimeter on the limit switches but I do not want to manually open the roof here in winter and get the same issue with bow latches. I am getting an open circuit reading on the fwd soft top s84/1&2 But not sure am I doing it correctly
I will check that thread out
Junior Member
Joined: Jul 2024
Posts: 34
Likes: 4
From: Colorado Springs, CO
1997 SL320, 1972 TR6, and 1981 Euro 230CE
BenzWorld has a dedicated forum for Electronic Systems Tools for Diagnostics
Thread Starter
Newbie
Joined: Nov 2024
Posts: 4
Likes: 2
Mercedes R129 SL320 1996
So it appears that the parasitic drain events produced a low/dead battery and that is when the problems started. Did you replace the battery with a new one?
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
Getting the STAR C3 mux working would be tremendously helpful. Did you end up with one of those cables that does not have all 38-pins wired? Perhaps your best bet is to get the faulty cable situation resolved so you can read/clear the RST fault codes.
FWIW this link has multiple threads on the Soft Top problems and the forum is much more active than this one
Useful Archived Topics
It sounds like you have done a lot of research already and tried all the usual "reset" things, etc. I know how frustrating this can be as It took me three months to finally get my own top to work automatically after buying the car in August. Mine was mostly failed hydraulics and it's still not completely right but getting there.
I thought long and hard about buying the C3 mux bit from China but in the end purchased the iCarsoft MB 2.0 scanner w/38-pin adapter. About $200 from Amazon. It has been able to read/clear the RST module and although it's not as capable as the STAR setup it still seems to cover quite a lot. A compromise solution I guess.
removed cover and adjusted the lever to the switches by about 2mm and hey presto fixed. ECU was seeing the top unlocked and would drop windows when battery reconnected and inhibited roll bar.
thanks for your help I have learned a lot about these roof now
