Mercedes battery drain power seat module fix. W203 

Hello readers, this happens when the master power relay inside the seat computer fails, This fix does the job but is not recommended for long term use. Use a relay on the main power wire. You have a mains, switched and earth so all wires are already there to add the relay. Great video, very helpful.

Is crazy that till this day 4 years there’s not another video on how to do this procedure besides this one and not all the Mercedes have the same layout I appreciate what this guy did but honestly I’m gonna start recording from now on whatever I learn to help the rest of the Benz community..

Thanks friend you just saved me 500.00. You rock

Easy to do. Should be noted that if you raise the seats up before removing the battery neg, you don't need to unbolt the seats.

My son bought a used C 320 wagon. he was told buy a very shady A hole That the car was in excellent condition. so far 1000.00 trans services at a very good independent MB shop...So the passengers seat was dead and the plug to the module was unplugged and we found that it drained the battery if it was plugged in!@@@ I searched and found your video and when to pick a part yesterday found a module and pulled out of a C 240. last night seeped it out and like Magic in seat came back to life and works perfectly, it took us 20 min!! I paid 20 for the part with 30 day warranty!!!!awesome !!@ Thank you so much for savings us time and money $$$$$$

Been looking for a solution or fix for the seat assembly module with battery drain.. I just finish and did mine.. will wait overnight see if it still drain my battery.. thank you for the good information.. and also I have 2003 W211 E500 just incase other model can try this

It worked praise the Lord, thank you sir for you knowledge

Found a w211( e class) 2003 for 1200 run n drive . it would he a great purchase after watching this video ! Thanks

Are these instructions for just the passenger seat? Only see these wires on the passenger side. Driver side has the brown, black/yellow, and red yellow wire. Working on an 03 C230 sedan

I have a battery drain not sure where it is 2006 e350 .... I don't adjust my seats everyday ....could I just pull the plug to the module to see if that's the issue ?

My accessory does not power when car is on, any idea?

Had the same issue w my C55 but just disconnected the plug, instead. Have to try this someday🤔

Thank you very much, my friend. I was having the same issue with my 2010 Chevrolet Impala 9C1 (Police Package). It turned out it was the faulty module of the driver's seat that was silently draining my battery; I unplugged it, and it fixed the problem. Your video was very helpful. God bless you.

Great video. This turned out being the case in my w463. Similar build in terms of systems. My only difference is that my seat harness only has two wires going into the module. A solid brown and a stripped. Any idea which is their designation? Thanks!!

this apply for w211? got a 2003 e 500 driver seat not moving window works then s500 2000 passenger seat down like my girl an i just fucked!!

I’m really hoping this is the issue with my 2003 w203. Will try and update, thanks a lot!

Yes sir" this is a good remedy, should have known this before buying two new battery's, and an alternator. Then payed a guy to install alternator and some lower ball joints. Total bout $650.00. But my brushes on the old alternator was very worn. Thanks

Greg does it work to mercedes benz C300 2009? Just got new battery 3 months ago. I notice park light comes on by itself.

Hi guys….. nice video and fix except my 2003 clk320 only has 2 wires hot and ground. Any suggestions on how to fix?

Can you just unplug it if you don't want to move the seat... Just wondering

Thanks Greg, the solution video worked for me perfectly. It took me about 20 minutes to fix the issue on mine because I was about to get rid of my 2003 E320 Sport before I buy a new seat module. Thanks again

I had a 2004 clk55 AMG. A beast it was. I had this same issue , it's one of the reasons I sold the car. The car needed to be jump started every day. Pain in the ass. I would have definitely tried this fix if I would have known about it then. That car broke more times then I can even count, while I was maintaining it, and throwing serious money at it. It was my worst purchase yet.

How do you know which seat is problem

I have a 2001 c320 but my wires are not tht color i have a white/red,brown/yellow and a yellow/red

RU-vid is my bestfriend! Thank u

Did this on a 2003 E320. Worked like a charm! Thanks bro!

My W211 2007 E350 has only two wires black and pink. Could you please help me troubleshoot this?

U have to send me link to those door sills plz they look awesome

Mine doesn’t have the Christmas wire (red and green). Just brown and black with blue stripe. Now what?

Does not look like a hack job to me!

Very clear and informative - thank you .

I have a C230 Compressor, it flattens my battery, but it does not have electric seats. Is there anything else I can check ?

Thank you very much for these easy instructions for this fix. I had a heck of a time finding this drain turned out to be pass seat module. Thanks to you, all fixed up. Great job sir!

Why not just disconnect it? It’s not like multiple people are driving the vehicle

Can I just cut off green and red and not connecting it to the switch power cable, wouldn't be the same. Completely without green and red.

I have the same problem but on the driver's side. If I cut the cable on the driver's side should it work?

Greg, thank you very much for passing this tip

Worked for my CLK500 W209 thanks a bunch mate!

Even quicker and easier is to remove the relevant fuse. Doing so means you can't adjust the seat, but the heated seat still works.

My cls550 battery keeps dying I replaced the alternator and battery and still dies after sitting for a day or two....any suggestions? And no mechanic i taken it to know what’s actually causing the power drain...

Nice video, but they have different power supply , I mean fuse. 1 is 20amp another is 30. so you give on 1 wire 50 amp ? Can you imagine when seat heating is on and you want to change seat position, so all motors be working, I think to much power on 1 wire.

I'm assuming that I have to do both driver and passenger sides to get the SRS light to turn off with this method?

I’m having this problem with my 2018 CLA. Dealership quoted me 1600 to replace driver seat module. Would this trick work on my newer vehicle, or no?

I bought an used module at eBay for about 70 bucks and it has been working fine for years.

So instead of hooking a ammeter up in series to the battery to chase down the draw can I assume the seat module is the culprit if the seat still moves with the switches after the car is turned off and door is shut?

I have a 2008 c300 battery draining, alternator, battery and starter is fine but glove compartment light is out and trunk light is staying on, I unplugged the light by the fuses in the trunk, got home and car still didn't crank but I can boost it off it'll run all day until it sits for a while. Do you have any idea what's going on?

I'm hoping this is the problem with my W209 battery draining... thanks for the video.

Can I just pull the fuses or those harnesses until I can replace the module?

Does this hack bypasses the seat module? I have a Mercedes-Benz w209 that has a bad electric seat. The bottom part of the seat doesn't want to move forward and backward, but can hear the relays clicking. The backrest and the headrest are operating fine. I have replaced the door switches as someone told me that this is a typical problem but It did not resolved it, issue remains.

Thank you very much. it's great knowledge. So I have check may car (W203 AMG, year 2004) I can see red-green (at positione 1), black-pink (at position 3 on connector), wire on passenger seat(my car right side drive) it should not a problem todo. But on drive side, there is different color of wires. Can I do the same even different wires color by making connected position 1 and 3 together?

Doin it to my e320 2003 sport tammaroe hopefully goes well thnx for vid

What size/gauge tap connector was used?

Also how can you determine if it's this problem as it can be other parts causing this, is there a way tti test it with a volt meter? Thanks in Advance I'm just tryna do this myself and I don't have a clue what to do

Does the switched wire have an appropriate fuse and wire gauge to power the seats? Has anyone had any long term issues with this?

My battery died Monday and I think it's because of this issue .

Hi there. Engine must be on? Or just 1st or 2nd contact? Thanks

So does the Christmas wire have to be splice into the switch on wire or do you just cut the Christmas wire alone ? Help?

Thanks easy to do and works great.

Ok i have a 2003 clk 320 and I only have a Brown wire and white and black wire im missing the third wire .. should I have 3 or certain models have certain wires

If u do so youll have intermittent lock unlock when outside the car

Work fantastic except my srs light comes on permanently. How do I remove it?

I have a battery drain on my o4 c240 I did battery drain test disconnected the wire to the sea module and my drain is still thier ,my codes are for oxygen sensor heater circuit .,

How an we're do I get the blue clip thing at

Hi, On my w211 it's the driver's seat and I have the (easy entry feature) option but I wonder if I do like you, after switching off the ignition will the option (easy entry feature) work or seat will not move after switching off the ignition?

My seat don’t move does that can fix it?

Does it make a noise too cuz i can hear a noise under the seat

I only have two wire’s on my plug, one is brown and the other one is red with yellow, could anybody help me how to do the same thing he did but only with two wire’s

Which side of the seat should i unplug...

Nice video! Wondering why we are connecting switched with constant. Isn’t cutting the constant the actual fix? Just asking!

Having the same problem . just checked the voltage on it and it draws 12v on both driver and passenger . Disconnecting it should fix the problem ? Until I get a connector ?

Great video, thanks. Do you think a faulty Secondary intake air pump relay could also drain the battery?

do it work just disconnecting the whole thing? I dont care if the seats dont move.. or can we just pull the FUSE?

Hey I just unplugged both driver seat and passenger seat and I'm still having draining problem. Any suggestions? I thought I would do this after I knew that was the problem. That should have fixed it shouldn't?

Many thanks for sharing your info 🙏

Good fix just scotch locks are horrible. way better options out there for a better connection

Do I need to disconnect the battery when doing this. Plus can I drive the car if I unplug them permanently and no fault codes will show?

Hey i have a c300 with red in blue wires are they the same as the christmas color wires???

I have a 2003 E320 can this be done to passenger and driver seat modules?

interesting i thought you would snip it at seat connecter side,my c32's got this problem but i rarely drive it so leave it unplugged, but thinking of selling it so thought i better get it sorted

Hi i have c240 seems like i have this problem, is there modules under each seat or just one? Thanks

Also my central locking module is drain the battery any pointers on that?

Worked like a charm on my 2003 E320. Got a quote for $800 to replace the module!

would stop draining your battery if you just unplug it ?

The blue clip you used to connect the two wires is called what? Thanks

Great video btw bro

Do we have to expose the two wires by splicing their insulation and then crimp them?

Great video just had this problem today thank you

2002 c320 wagon (w203) Do I have to do both seats?

If i were to just unplug the cable would it stop the drain ?

why cant you just cut the christmas wire and just leave it at that? will it sense there is no electrical output there and throw a code? won't the electricity coming from the switch wire still just be going into the christmas wire output anyways? a little confusing for me :(

I have no idea to get under the seat to disconnect the module. Wouldn't be easier just to pull the fuse? I've pulled F001 and F002 and the battery is still draining and the seats still work. Does anyone know which specific fuse to pull if I don't care about the seat working (which I don't)

Srs fault after this mod.why?

Would just unplugging it completely solve the issue if indeed this is the issue? Thanks

Do you need to disconnect battery first?

Are the seats supposed to move with door open?

Great 👍

In uk this colours correspond to passenger seat, driver seat different colours. Do you have to do 2 of them?

I have a 2004 E500 and im getting a no start on and off pretty randomly. Sometimes itll drive for 7-8 days before I need to get a jump , and sometimes 1-2 days after ive charged the battery. I had the battery and alternator checked and theyre both good. How do i know if this is even the culprit to begin with? and which seat if so? any help appreciated. thanks. btw i did do a parasitic drain test on the fuses and nothing conclusive came up.

Tks a lot dude!!

I have problem with battery drain on a Mercedes clk. I have unpluged the modules under the seats but I still have problem with battery drain. What could be? Any advice is helpful. Thanks