I have a 300E with strange electronic seats. They can only be adjusted when the doors are open. I have no idea why it does this but man is it annoying. I might be going 65 mph down the road and have to open the door to adjust the seat...

Any ideas on how to fix this???

I bought the car in April last year and it's been this way since I bought it...

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Ty H.
'87 300E 135K Miles

Check the wires in the door harness. They have been known to fray over time.

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1999 E300DT (131,800) 154,000 Black on Black SOLD

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They don't work when the car is running?

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

They will work when the car is running, but the doors have to be open. It's the same on both sides--the door has to be open for the controls to work at all. It's strange. It doesn't seem like the wires are kinked since it's the same on both sides, although I guess that is possible... The door just has to be slightly open, as if there is a sensor that knows the door is open and allows the controls to work...

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Ty H.
'87 300E 135K Miles

Common symptom on w124,old wires in the door are cramped most likely.

That would make sense if it were one door, but for both doors wiring to fail at the same time???

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

When you open either door, the interior lights come on; this may be some sort of power issue. Some how the seat controls may be getting power from the interior light circuit or something like that. Just an idea. The broken wire thing usually happens to the driver's door first, as it is opened the most often.

Any resolution on this problem?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I'm experiencing the same problem on my 87. Everything was fine until I took down the front headliner a while ago and accidentally screwed one of the left visor screws through the small wiring harness that goes up the a-pillar to the dome light. This caused the interior light to stop working, which was easily fixed, but my seats still only operate when the door is open. I'm starting to think it was just a coincidence, I took it all apart again tonight and didn't notice anything wrong.

This also caused a fuse to blow, I can't remember which one now, possibly #9.

I checked the E & F fuses for power (the fuses that power the seats) and they only have voltage when the door is open, regardless of if the ignition is on or off.

EDIT: I just was looking at the wiring diagram and the power seat diode is likely the culprit. It is in the far back right of the relay box, you'll have to remove those 6 phillips screws on the plastic box to get access to it.

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-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

did you ever find out if it was the diode that was causing the trouble?

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'87 300D new to me
'85 300D Sold
'83 300cd Sold

Yes, it was the diode on my 1987 300e.

Now I have another problem. The powerseat will not lower, only raise. I stripped back the insulation on the wires to the motor under the seat. However, something unusual happened. I have 12v between both the White and Black wires and ground when pushing the control button down... Odd. Sounds like a door switch problem? Or am I reading things incorrectly?