fuse 43 parasite loss e46 m3

[ShaunG]

Hi Everyone,

I've been ignoring a long time slow parasitic battery drain with my E46 M3 and finally got around to finding out what it is. It appears fuse number 43 which is part of the instrument cluster is the culprit. We go from .09 to .02 when that fuse is pulled. Any idea on what to do next?

Thanks!!

[heinzboehmer]

This is probably not too helpful, but I just solved my parasitic drain last week. It turned out to be my radio (the actual cabin head unit). I saw a current drop when removing fuse 41. Replaced the radio and drain went away.

Try disconnecting the cluster and see if the drain goes away. Looks like fuse 43 is part of the OBD II system as well. Do you have anything connected to the OBD II port? Like a bluetooth adapter or something.

[kokgo20]

Bluetooth adapter was my problem in the past

[ShaunG]

This is probably not too helpful, but I just solved my parasitic drain last week. It turned out to be my radio (the actual cabin head unit). I saw a current drop when removing fuse 41. Replaced the radio and drain went away.

Try disconnecting the cluster and see if the drain goes away. Looks like fuse 43 is part of the OBD II system as well. Do you have anything connected to the OBD II port? Like a bluetooth adapter or something.

Hmm.. I do have my Blue tooth OBD reader.. I'll check tomorrow!

[heinzboehmer]

Hmm.. I do have my Blue tooth OBD reader.. I'll check tomorrow!

Wouldn't be surprised if that's what it is.

[Obioban]

Hmm.. I do have my Blue tooth OBD reader.. I'll check tomorrow!

That’s almost certainly the issue.

[ShaunG]

I went from .09 to .04/3 when I unplugged my OBLINK MX. It dropped to .01 when I plugged fuse 41(radio/nav)

Thanks to everyone who replied!