Driver seat doesn't work in both directions
 

'97 E420 driver seat will move forward with manual switch, but not backward. Seat WILL move backward to memory positions using memory switches, so seat motor appears OK.

Replaced door switch assembly ($150!), but problem still exists.

Any thoughts? Thanks

You hit the nail on the head. The switch is at fault.

Have you tried running the seat all of the way forward?

Mine was doing just that
 

I was able to dig the switch out and clean it up. Don't know if it' like my 190e, but the buttons just pull off, and there's a plastic snap ring, then two screws and a couple of plugs. I carefully pried off the plastic covers and sanded the contacts in question. It works just fine now.

hard cracked insulation
 

1. Hey guys he said the switch was replaced remember…

2. It could be your wiring; your car is still young but never know. When the wire insulation gets old they gets hard, every time you open and close the doors the wire is bending back and fourth like it’s designed to do. But when the insulation is hard it can brake, now picture the wire bending at a sharp angle, in time the wire will severed.

3. To confirm this take the switch out and jump the points one way for back and the other way to go forward. Fine the fault one and ohm it out. You don’t need to replace the whole harness just between the broken one with another wire and a crimp kit set.

Good luck,
Thai GI sends…

Took the advice of MB Doc above and ran the seat all the way forward. I have no idea why, but that fixed it.

Thanks for all the help -

The W210 "E" class cars have a limiting feature built into the seat so that you don't SMASH a tall persons feet OR legs by moving the seat back(OR forward) too far. IF the computer feels that the seat motor is drawing too much current then it will stop there every time until you run the seat all of the way forward OR all of the way back so that it RE-learns its full travel. Neat HUH!

GLAD that it fixed your car!!