MB type 129 electric seat stuck
 

on 1991 MB 500sl seat doesn't want to move forward when extented to max rear position. Motors keeps turning and seat moves in all directions except forward. In such position it is impossible to remove seat alltogether.

To start with you don't remove the entire seat on a R129 SL!

At the front of the seat with your head on the floor mat looking at the seat frame you will see 2 phillip headed screws that secure the seat lower cushion. remove those 2 screws & bingo you can find what has broken on the seat drive.

If your motor is turning but not moving the seat, then you likely have a broken nylon gear in the ball screw adjustment mechanism. It is definitely a DIY repair.

500SL drivers seat stuck foreward
 

Hi folks I'm new to this forum and appreciate any help you all might be able to give.

Actually the only thing working on the seat is the seat bottom and head rest raises and lowers. Won't move fore or aft or will the back --- might get a small monkey into the seat but that's about it! ;)

Looked as suggested for the removal of the two screws but no way can you remove the front cushion only thing is you can remove the lower skirt which shows you the front of the motor/servo which still are inaccessible.

We tried a new switch not the problem. Looks like a seat removal any suggestions MD builds these like a 'tank'!

Thanks

Tom

The screws are there Tom. They are usually a goldish tone philips head, but occasionally you see them replaced with hex head. Look at the front of the seat, way down below the front of the cushion. If they aren't there you can lift the front of the seat out, if you want to try that too. But I'm sure they are there. If the passengers seat works, try looking at that one. I'm sure it's hard to spot if the seat is adjusted all the way ahead.

Gilly

Thanks Gilly, I will take another closer look --- the passenger works I'll check it out at least can get down onthe floor over on that side.
Tom

Gilly a big thanks again they were hex screws needed a mirror to do the drivers side since jammed all the way forward.

Now the fun part, when you try to move the seat control button to back it believe it or not the back of the seat wants to activate and when you try the back of the seat control button the seat wants to try and engage to the rear but can't do it. The seat button does want to still move it forward but of course its jammed but it will still activate the raising and lowering of the bottom cushion.

Appears something is crossed somewhere -- maybe a diode burned allowing the signals to get screwed up.

Any thoughts would be appreciated.

Regards,

Tom