[klovaaxel1000]

Hi everyone, first post here but this forum has been very helpful the last years of owning my w220 so I hope someone can help.

So I might have the dreaded battery drain issue...
While trying to figure out what might be causing it I sat in the car while it was completely shut off and locked and noticed that the instrument cluster was moving all the needles at some time intervals, I have read other posts on the forum saying that they have battery drain from the instrument cluster but then as I understand it doesn't shut off at all and is still lighting up, mine is completely dark and apart from the needles moving seems to be off.

Here is a video of what's happening: Video

Does anyone have any idea if this is normal behavior or what's causing this to happen? I don't have access to Star diag but my Generic OBD2 scanner shows no faults

 

[cowboyt]

Generic OBD2 scanners won't show any faults. You need something better, like SDS, to troubleshoot this sort of thing. I'll bet you've got codes for the instrument cluster.

 

[klovaaxel1000]

So for future reference, this problem was solved by dehumidifying the trunk and interior.
I did not get a chance to read the codes with SDS as the mechanic I usually go to is out sick and the dealers in my area are absolutely terrible...

After this post I also experienced some issues with the command system and speakers, however, these symptoms went away by themselves but I would assume that would be because the car was in a less humid and more temperature-controlled area. In the past, I have had issues with frost buildup on the inside of the windows and sunroof so I guess it may be my car that either has some small leaks that build up over time or condensation from the fluctuating temperature changes.

Something I might need to look into in the future but for now a couple of salt dehumidifiers did the trick, no more cluster issues, no more command issues, and most important no more battery drain!

 

[tim687]

How funny, I had the exact same issue a few weeks ago

 

[wallyp]

The first suspicion is the dreaded HVAC plenum overflow under the carpet. If so, you are a very lucky man - the results of that are almost always much worse.

 

[tim687]

The first suspicion is the dreaded HVAC plenum overflow under the carpet. If so, you are a very lucky man - the results of that are almost always much worse.

This isn't the engine bay air intake for the AC system, is it?

 

[wallyp]

Yes.

 

[tim687]

Well that wasn't clogged on mine