W124 electric seat not gping backwards and forwards

[Celicasaur]

So i went to replace the carpet in my car today (don't ask) and was delighted to discover that the electric driver seat refused to go backwards. In the end I painfully managed to apply 12v directly to the connector under the seat via some trial and error which got it moved, so at least I know the motor is working.

In order to solve this issue, would I be right in thinking that the only suggestion would be to follow the loom back to the switch and looking for the culprit? My money's on the switch area I suppose, but who knows. I'm not normally good with electrics although I did check the fuses and got 12v with my multimeter so I guess that rules the fuses out.

I'll be sure to post the solution here once I figure it out.

 

[219]

More than likely the switch , I’ve known them to fail before , also the easiest thing to replace .

Just possible there is a break in the wiring where it flexes around the door hinge . You could use a meter to check continuity of the wires from one end to another - you can identify the wires by their colour codes at each end .

 

[wrdcc01]

Can't leave us hanging like that. What happened then?
Was the seat working beforehand or didn't you use it recently? The fault is most likely the switch but you may have just upset the multiplug on the seat module.

 

[Celicasaur]

Hi guys, sorry the weather has been so nice over the last few days, that I'd spent most of my time painting panels for one of my other cars. Ahem...what an amazing country this would be if the weather would just be a bit kinder to us.

Anyway, so yeah tbh I'd never had an issue with the seat in my years of owning this car - it's always gone backwards and forwards when required. However of course, the amount of times that I need to do that, given that I'm the only driver is fairly few and far between, unless I'm putting something large on the back seats etc

I checked the wiring from the plug behind the door card with the buttons, to the plug that connects under the seat (blue and purple wires for future reference) and continuity was fine. I guess this means that I need to order a new switch....? Oddly enough, I applied 12v (ok, more like 11.3v) via my spare battery directly to the seat like how I did over the weekend and it didn't move....spooky.

Here are some pics and part numbers:













I'm not quite sure what the part number for this switch is supposed to be though...any ideas? looks like a bunch of connector plug part numbers. Either that or I need to get the whole black block thing, part number 124 821 28 51?

 

[wrdcc01]

You would have to get the main switch block unit but that motor sounds less than 100%, might need a bit of lube! If you aren't getting 12v out of the violet and blue when operated then it is the switch unit.

 

[Celicasaur]

Well, so the plot thickens.

I got in a huff yesterday and needed the car off the driveway, so I figured that I'd refit the seat and manually apply 12v with a good spare battery into my seating position again etc.

I plugged it back together...and it started working as normal via the switch on the door

I hate this car.

 

[Martin 1]

I'll bet you don't really ! Your problem, like a lot of others, is that you're applying logic, it's a car, albeit a nice one, logic doesn't apply.