Okay here is the follow-up.

1. Checked the seat and there is power with every function except when try to put the seat back up. When trying this function, the is no power to the motor.

2. Is there a control unit the controls power? I reached the door switch and it didn't make a difference.

3. Also tried reversing the polarity to the motor and it didn't make a difference.

Any further suggestions? Did I miss something?

Thanks

Ron

__________________

I have an '81 300SD. My driver's seat stopped moving front to back and back to front. It went up and down properly and the seat back moved forward and back; just refused to move forward or backward. I worked and worked cleaning the switches, etc. and nothing fixed it. Finally I removed the seat, turned it upside down, and hooked wires from the motor to my battery charger. After a few minutes of exercising the seat every way possible, finally it moved front to back. Like magic. I put it back in the car and it has worked perfectly since. I am thinking it was a bit rusty or hit a flat spot on the armature or something. But that was some five years ago and it still works fine today.

Maybe you just need to take the seat out and hook it up to DC power and exercise the motors for a while.

I need to replace the seat control switch in my 85 300SD Driver's side. How did you replace your switch. I have no clue how to access it and am concerned about ruining the Driver's Door wood paneling around it.

Real easy. Just remove the door card and the entire switch and wiring is inside. There are a lot of posts about removing the interior door handles and door card here; try looking under replacing the window regulator or maybe sliding jaw. As I remember I just cut the wires and unscrewed the old switch and screwed in the new switch and patched the wires. My only problem was that the new switch was a bit newer and it had one extra wire. A simple question to the forum and someone told me where to patch that wire. Has worked ever since and that was several years ago.

Will see if I posted any pictures. Do not remember.

Found it. This should help with the wiring.

Need help quick - 81 SD seat switch wiring wrong

Ron59B - did you ever get your seat to work?

No not yet....

__________________

I replaced my seat with a seat out of a car from the bone yard. I did notice the replacement seat was making a noise. I checked it out and discovered one of the servos or motors, at the base of the seat back, was cycling constantly. It is trying to move the seat or something? Any suggestions on what to check? Maybe a possible fix?

__________________