Battery drain - .13 amps with all fuses removed?

[JGood]

My battery is draining within 24 hours. I removed EVERY fuse, and am getting .13 amps drain (hooking multimeter inline with battery + and cable +). Pulled main and fuel pump relays... still .13 amps.

I have an aftermarket electric fan and XM radio/Pioneer head unit. Removed all that, checked related wiring, still .13 amps.

This just started one day, very random.

Any ideas?

[Jordan]

Several + cables connect at the junction in the engine bay. Remove them one by one to see which subsytem they feed is the one with the draw. This will narrow it down a bit more.

[JGood]

I narrowed it down to the power wire going to the fusebox.

Problem was, I was removing fuses 3-4 at a time. So I emptied the fusebox and installed them one by one. Turns out fuse 21 and 27 need to be removed at the same time to clear the .13 amp draw.

The only thing those fuses have in common is the OBC. So I'm going to yank that now and see what happens.

Any other ideas with these two fuses being related? I'm just going off of the owners manual fuse diagram, so I'm not sure if that's 100% correct or not.

[EMRtek]

I happen to have the same problem on my car, I started pulling fuses and it seems that is also related to fuses 21 and 27. Let me know if it turns out to be the OBC, I have not tried that yet.

[JGood]

I removed the OBC, head unit, and instrument cluster, still .13 amp drain. All the wiring under the dash looks good, jiggled everything a lot as well.

If I'm using my multimeter wrong - if it's set to read voltage across the terminals, it's rounding 12.x to 13... that wiring should supply the clock with constant power and everything would be normal...

I have an ollllllld, but good, radio shack multimeter, not 100% sure if I'm setting it correctly to read amps. But I turned it to every other setting possible and never got a reading, and my battery is draining, so wtf?

[StereoInstaller1]

OK, first BUY A TESTLIGHT. Do NOT use a DVM to find a draw, use it to test the draw after you found it. Lightbulbs are your friend!

OK, so your service manual is here. Page 21 shows your fuse 21 runs all the domelights, trunk light, glovebox light, active check panel, radio, chime module and instrument panel.

Page 24 shows fuse 27 running the OBC horn, interior light timer, factory amp and central lock module.

If you have a door lock that is not moving through 100% of its throw, the lock module will continue to attempt to lock (or unlock) the door...just as an idea.

Seriously, pitch the DVM. You are using a microscope when all you need is a pair of glasses.

Luke

[JGood]

What is the best procedure for locating a draw with a test light?

My drivers front lock has always been shitty. I don't lock the doors, haven't for probably a year now. The key gets stuck if I try to.

[Stevie30]

Seems to me that your trunk light is staying on when lid is closed. Check switch for proper function. Remove bulb and recheck current draw. Good luck!!!!

[JGood]

Seems to me that your trunk light is staying on when lid is closed. Check switch for proper function. Remove bulb and recheck current draw. Good luck!!!!

That wouldn't really make sense as fuse 27 doesn't have anything to do with that.

I'll hook up a test light though, and make sure I really am seeing a .13 amp draw (and not reading 12v). But... even if I am reading 12v between the + post on the battery and the + cable, wouldn't that mean there is a drain?

[StereoInstaller1]

HOW TO USE A TESTLIGHT TO CHECK FOR A DRAW:

Disconnect the negative terminal from the battery.

Connect the testlight between battery and negative terminal, as in clamp the battery post with the clamp and stab the probe into the negative terminal.

If the light is on, you have a draw. Pull fuses until it goes out...of course, make sure the doors are closed, key is off, etc.

Chase the circuits that the fuse runs until you find the issue!

Luke

[JGood]

Connect the testlight between battery and negative terminal, as in clamp the battery post with the clamp and stab the probe into the negative terminal.

what?

[StereoInstaller1]

Hook the testlight up between the battery and the car, same as you would a DVM.

[JGood]

I borrowed a new high quality automotive tester from a friend, and was able to accurately measure the draw. It was fuse 21. Before, I was seeing 12.5v across the battery which was rounding up to 13, which I thought was amps.

I have a 60mA drain off of only fuse 21. When I open a door, which turns on the interior lights, I get like 1600mA. Is 60mA a problem?

[jlevie]

60ma is typical parasitic draw on a newer BMW and should not a problem if the battery and alternator are in good condition.

[StereoInstaller1]

60ma is typical parasitic draw on a newer BMW and should not a problem if the battery and alternator are in good condition.

QFT...and your story is why I say to use a testlight!