Originally Posted by jecampnelln500
if i leave the car for about 5 days the battery will go dead. I took it to auto zone and they tested it and the batt was OK . I drove it today 150 miles and after I got home the batt was at 12.6 / could this be a gorund problem.
Hard to tell....if the Battery is 3-5 years old...& not driven for long periods of time..... your battery still may be bad...BMW's are known to have some low voltage drawing power...example....the interior ambient air sensor fan runs a little after you shut down your car....I know on older model cars, you can check for a short by disconnecting the negative battery cable & attaching a 12volt test light from the unattached neg. batt. cable to ground....with everything turned off on your car, the test light should not come on, if any, very dim & for a short time, if the light comes on somewhat bright, then you have a short....then to find it, you then start pulling fuses to find it...