eclipsed

Does any one have schematics of the seat control module? or a test procedure to identify which one is draining current. Other than unplugging one at a time and wait 24 hours to see which one killed the battery. Thanks in advance.

Gramma_Benz

In my experience:

what a bad seat control module normally does is keep the command system fan on 24 hours.

Normally, once you shut off the car and pull out the key, the fan behind the navigation stays on for about 3-5 minutes(I think) and then shuts off automatically. When your seat control module is bad, it stays on all the time, thus draining your battery.

Trouble shooting:
Maybe try disconnecting one side(I think I have read that the passenger side goes bad most often) and then take out the key. Listen closely for the fan behind the Command screen. Wait 5 or so minutes and it should shut down. If it does, try disconnecting the other side.

Side note: Depending on how long you have this problem, it may also put extra strain on your alternator thus causing it to fail prematurely as well. Best to take care of it ASAP.

Good luck!!

eclipsed

Thanks for the reply, I wish I had command, just the standard cassette and cd changer system. Both are unplugged tonight and I seel how it acts in the morning. I am worried about the battery being polished off as it is original. I have been unemployed all summer and I have to drive 300 miles to St Louis for 2 weeks of training and dont want any thing serious causing me problems on the road.

Gramma_Benz

Before I found the solution, I was disconnecting my negative terminal on the battery every night and reconnecting it in the morning.

TemjinX2

i wrote a diy fix on my sig for the passenager side. I haven't done the driver side yet, but i'd imagine its the same wires on the front harness.

c32used

Follow ^^his^^ instruction.

raymond g-

i was in a hurry but quickly grabbed as many wiring shots as I could. if you
need more, let me know and i'll try if i have time.

TemjinX2

i checked the drive side today. The same solid brown and brown/red wires exist on the drive side too, separate from the other bundle of wires.

Note, you don't need to disconnect your battery terminal. All you need to do is disconnect the front harness to the seat control module. Its directly under your seat.

Its the solid brown and brown/red wires that causes the drain. you only need the solid brown wire to activate the control modules.

my diy for the lazy.

https://mbworld.org/forums/showthrea...55#post3068555

eclipsed

Thanks for the schematics. I hope to find the internal reason for the failure at the component level if possible. It would be cool if we could rebuild them or replace the bad circuit. For now Ill use the relay method of MR X

TemjinX2

yeah thanks for the schematics raymond. Would've saved me a lot of time, if i had this before.

TemjinX2

i would rather just fix it with a $3 relay and some wires then pay for them to be rebuilt. I would imagine the cost would be a lot more then $20.

hammertime21

Beckman Technologies already knows what goes bad inside the seat module. They can fix them. But I believe they only work with actual shops, they wont sell to individuals off the street.