Parasitic Battery Drain [SOLVED - old battery dying]

[sb2665]

Hi my 06 M35x brake, slip, and VDC lights started to illuminate and stay on when driving. While lit my cruise control is inoperable. Initially they would come on but after a few cycles of operating the car (driving to destinations) these lights would extenquish and I would have my cruise control back. Ultimately they have stayed on all the time, I have no cruise and now my battery dies overnight. Any similar problems out there? Thanks!

[Ilya]

Those dash lights stay on even when the car is off?

[sb2665]

Stay on (Brake, Slip, and VDC) while car is on and I have no cruise control. Pushing VDC button does nothing.

[EdBwoy]

Off the wall question - does your horn work? Do you have a rear camera?



Also, check the condition of those 2 switches under your brake pedal.

[Sstupid]

Sounds like a dead cell in the battery. If it does turn out to be a parasitic drain, you can find a good how-to video for that on YouTube. Eric the Car Guy has a good video on tracking one down.

[sb2665]

So here is what I found out. The dash lights staying on problem was coincidental to my battery dying. When I removed my battery I discovered that it was going on 8 years old! Time just rolls on. I replaced it in 2010. So my Brake, Slip, and VDC lights were still lit after I replaced it. After a Youtube search I discovered that this was due to my brake fluid level being at the minimum level. There is no leak just a big drop due to normal wear of my brake pads. So this is just one of those kiss situations (keep it simple stupid). I just assumed the battery was being drained by a short of some sort since it was in its final death throes coincidental to the brake fluid level thing. The dash lights initially would come and go at the same time the battery was getting weaker and weaker. I think initially the brake fluid level would rise as it heated (thus turning the dash lights off). Ultimately (when the brake fluid level dropped low enough) they stayed on continuously. Anyway the upside is that BJs Exide batteries are damn good batteries and the battery fluid level thing is a good thing for M owners to be aware of!

[EdBwoy]

Awesome. Thanks for circling back with the solution(s)

[Sstupid]

So.....I was right.