Power seat motor

I'm having a problem with my seat as far as the height adjustment. I've replaced the switch and yet still not functioning as normal. I thought the back motor under the seat is no longer working. What is the best way to test the motor to see if that is the coz? The fwd & bwd, back and headrest works fine. Please advise if any one of you had encountered this before.
Thanks...

[Benzmac]

I have seen the tracks fail. You will have to pull out the seat.

Upon pulling the seat out, what's next? Thanks

mic-280 dose your seat motor operate? My 85 300sd had similar problems. Found problem to be the flex cable drive from motor to gear assembly, required complete removel of seat to repair.
John dudinsky
85 300sd
81 380sl

Yes, I believe the motor that tilts it up & down and forward & backward works.
However the one that really adjust the height w/c is the back part or the second motor don't really work. I'm just guessing that it's the motor or maybe something there that is preventing both arms to fold up and down. I've repalced the switch and yet same thing. So I'm inquiring on how to test or how to find out if the motor still good or bad.

[bill17]

First operate the switch in both directions and listen carefully to confirm there is o sign of movement at all. Also use a volt meter at the motor terminals if possible. If there is voltage when switch is operated, but motor doesn't turn, then motor maybe faulty. If no voltage, then wiring may be the cause.

My back rest didn't work, and the problem was traced down to a misplaced "socket pin" *inside* the wiring connector going to the switch on the door.

Thanks, I'll check on the pins.