Close

Q: Brand new battery dies if left for 24 hours. What could be draining the battery? on 1994 BMW 540i

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Having some weird electrical problems. The back up lights are not working. The interior panel lights (speedo) dim sometimes. The trip computer went into 24hr mode and then back.
(2) Answers
(2) Comments
Turned out to be (after 20 hours of work) a shorted out seat motor. It worked but was alway in the "on" position. Thanks for your input.
I would start by checked all the doors and trunk to make sure lights are off. Might have a big short somewhere making battery draw. Would take to a repair shop and they can install a meter to battery and start removing fuses to see what is making draw
It turned out to be something that took a master BMW mechanic 2 days to find. After pulling the primary fuse box and the secondary fuse box and going thru all the relays there was still a big draw. It seems that even though it was still functional one of the seat motors was in the constant "on" position. We have a combined 50 years of experience working on BMWs and neither of us had ever seen that. Replace the seat motor and problem solved.
Qualified Local BMW Shops
Qualified BMW Shops For This Repair
Didn't find what you were looking for?