Front Seat Adjustment

[C Holmes]

I have a '90 300sel. The drivers seat will sometimes work erratically. If I try to make it move forward it will go in short spurts a little at a time. Sometimes it works fine. Does not have any problem moving back, just forward. Anyone know where I should start to look or does this sound farmilier to anyone? Could it be a dirty switch? If so how does it come apart? Any help would be great.
Thanks

[jeffsr]

Start with the switch, but don't try to take it apart unless you have tiny little fingers and love little steel balls. Usually they get dirty or the contacts pit. In either case, remove the switch, get yourself some WD-40. Fill the switch up with this and run the little actuators back and forth, up and down, etc. The idea is to try and loosen or remove any crud, etc from the contacts. Finish the job by dunking the switch in some isopropyl alcohol, shake out the excess and allow it to dry. You can force it a bit with a hair dryer. If you get function back, then one of two things will happen. It will continue to work or it will fail again, in which case you now know what the problem is and you will have to replace the switch. This has worked for me in the past with similar devices.

I strongly recommend Acetone to clean the switch. Just go to any electronics store and buy some electronics cleaner, also called tuner cleaner at a TV shop. If you have a continuity checker, which is on, most newer multi-meters just trace the problem down the line.

[500sec]

hello.have the same problem with my SEC i believe it is the motor.if you tap the motor with a hammer will the seat act normally again?if so the motor needs some cleaning at the very least.

[C Holmes]

There's no noise from the motor, just will not move, that is why I think it maybe switch related. If I have to take the switch out how is this accomplished? Does the door panel have to be removed?

[jeffsr]

Acetone should not be used as it will dissolve the plastic and ruin the finish on the seat adjustor knobs. There is a difference between acetone and contact cleaner. If you read the label on the contact cleaner, you will usually see a warning about paint and/or plastic. Contact cleaner has a volatile hydrocarbon in it. Usually some form of methelyne chloride or carbon tetrachloride. WD40 and alcohol will not damage the plastic parts of the switch. To remove the switch, remove the trim around the switch/door handle. Believe it is held in place with a couple of screws. Gently work the switch out of the cavity in the door and remove the connector. After that give it a bath..

[Edited by jeffsr on 01-28-2001 at 03:53 PM]

I agree with that I was thinking the switch would be removed. However it would be a real good idea to pull the fuse if you are going to use WD-40 to prevent both sides of the circuit from opening and causing some real problems.

[jeffsr]

All of the suggestions I made assume removal of the switch from the door. There should be no electrical connections in place when dunking the switch in the isopropyl alcohol. Even with the switch removed, acetone is not a good idea. The odds are not in your favor if you try to disassemble that critter. Has little roller ball contacts, springs, etc, inside. Try treating with the witch's brew I suggested. If that doesn't help, then it is NG or there is something else wrong. Did I mention checking the fuses???