Electrics...

[Winso]

Not strictly speaking a VW issue but I'm sure someone can help! My E36 beemer has a bit of a habbit of draining its battery if it's left for a few days. Battery is fine as is the alternator so I know the problem's not there. I've tried disconnecting the alarm/immobiliser and that doesn't help either so I'm gussing there's a wiring fault somewhere.

What's the best way of finding what's causing the problem? I'm thinking I'd need to go through the fusebox when everythings switched off and see what circuit's are still drawing a current....? I'm not good with electrics and have literally no tools for that sort of thing. What do I need.... a multimeter?

[DCmk3]

What sort of radio/headunit is in the car? Perhaps that is draining the battery.

[sharki786]

i had same issue but mine would only last a night. turned out that the remote wire for the amp, just 1 strand was touching the + wire on the amp and when i was putting my HU on the subs would make a BOOM noise. i thought bit weird. so check that out

[grayboots]

You need a multimeter that can read amps, disconnect the battery and put the meter between the disconnected lead and the battery...(make sure you know your radio code). Dont turn anything heavy on like lights or try to start it or you will blow the fuse in the meter.
You will see the number of amps on the meter with everything turned off , by pulling each of the fuses in turn you will be able to see which circuit is drawing power.

ps....also check the general module under the back seat isnt sitting in a pool of water !

have fun