W211 Battery Drain Problem

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Endann

New Member
Joined
Jul 25, 2020
Messages
5
Location
Lithuania
Car
W211 E280
Hello, I have E280 W211 2006. Last morning I found my battery dead, out of nowhere. Now I got a new one and found out I have 1.43A current drain. However, when I remove my instrument cluster's positive or ground wire , car falls asleep in like 1-2 minutes and leaves 0.03A drain only. Maybe you've got any ideas what could be causing this? Not sure what to do next, worst case scenario I might install a relay that gives power to Instrument Cluster only when ignition is on.
 
None of the fuses off stopped draw? Many modules are communicating via instrument cluster...
 
None of the fuses off stopped draw? Many modules are communicating via instrument cluster...

Yes, actually Fuse #64 in the engine bay , which is 7.5A stopped the draw . Following that, it's how I found intstrument cluster being one of the problems. Later I tried CD Changer , the big screen radio, telephone module, etc., everything seemed factory and didn't do anything. Is there anything you could suggest me try out? Thanks for the reply!
 
hmm... can't remember similar case where cluster only has been culprit...

1.4A should still not drain battery overnight, or was the car standing longer?
 
I bought a car with 77Ah battery, and the day before I got white message with convenience funcionts temporarily disabled. Drove it a month before it happened. I still dont think 1.4A is fine , when it's supposed to be up to 30-60mA. Could anything be with overhead control panel ? I remember seeing some kind of fault on it , althouth everything works fine. And anything I could relate fuse #64 to the drain , besides Instrument cluster?
 
#64 is controlling climate control and exterior light switch

Edit: I just read the link above, confirmed 😁

And yes 1.4A is far too much. How much you car is charging?

WIS states that if draw is 1.2-2.5A it means a BUS is awake, so basically faulty component connected to instrument cluster should be found via fuse too.
 
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So basically following the fuse #64 I should disconnect every component giving power to it and see if it gets better? Or, since I found one of the culprits being Instrument Cluster, which I disconnect and it gets better, are there any diagrams what components are connected to Instrument Cluster so I can shut down them one by one?
Thank you for your replies!
 
You could try disconnect CAN connectors and see if either C or B will stop the draw. One thin possibility is MOST ring keeping cluster awake, recently one W220 had this fault (first I have readen though)

W211 networking, link for US forum https://mbworld.org/forums/attachme...ule-communications-networks-networking-1-.pdf
Thank you very much for the help! Tomorrow will do that, in the end I will let you all know what did help for others in the future
 

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