89 735i - Troubleshooting electrical problems

Currently battery draining down.
Was told it was an electrical issue by one mechanic, but not sure where to start. Battery is not bad, but unless cable is disconnected after turning car off it will drain down. Where should I begin to start to troubleshoot

do you have an amp meter?? you could watch the meter as you pull and replace fuses 1 by 1 until you get the largest drop. then check that circuit.

there's only a gazillion fuse boxes on the e32, so it shouldn't take too long...

you may also wish to check the e32.org site as well. lots more e32 specific info there.

i seem to recall that i had searched similar issues with my e32 and found that one of the modules had a common failure, but darned if i can recall that info now...

i'd try a search on the e32.org site, though.

good luck.



df

Thanks DF. I will keep you posted on the results. If you recall anything else please send it along - SetBMW

Originally Posted by SetBMW

Currently battery draining down.
Was told it was an electrical issue by one mechanic, but not sure where to start. Battery is not bad, but unless cable is disconnected after turning car off it will drain down. Where should I begin to start to troubleshoot

Just buy 5$ multimeter first!
Then check the current it's eating it should be no more than 0,2 amp when no lights are on and all systems are shut down. If it's 0,5 or more you've got a problem.
Could be anything: short circuited wire rotten wire, light bulb connection,
Etc.... Just try to disconnect all bulbs one by one check if current drops, and sooner or later you'll find where it is. I think it's some bulb wire touching the negative somewhere