Parasitic Battery Drain e53

[oldskewel]

Originally Posted by petebert

I left the battery unhooked overnight aaaannnnnd, the battery held fine. So now we're back to square zero. So what's the best way to test this starter? I haven't looked into the EWS much yet to see how the wires are configured on it.

What kind of car do you have? The V8s have different engine electricals than the M54.

[petebert]

It's the 3.0 and in a weird change of events it seems to have at least temporarily fixed itself. Maybe that's why I didn't find an amp draw the other day.



The battery had been losing about 1 volt every 12 hours. I was going to do more testing so I went out last night to get a voltage reading and it had barely dropped. Did another reading this morning and again the voltage has barely dropped.

[oldskewel]

For the 3.0i (only?), the B+ jump port in the engine bay is a 19mm nut. It also connects the 12V cable coming from the battery to the engine bay.

So if you were to unscrew that nut and separate the cable on the engine-bay side of it from the stud, you will isolate the starter and alternator from the battery, at least the B+ connections (no promises about the smaller wires).

Kind of unfortunate that the problem has fixed itself for now - it will surely reappear and the debugging will be tougher knowing it is intermittent.

But anyway, that simple unscrewing of the nut will mostly isolate the starter. From that jump port nut, a cable runs straight to the starter, and then another cable runs from the starter to the alternator, where it ends.

BTW, an alternator can also be the root cause of a parasitic drain. Similarly difficult to find by checking fuses.

[andrewwynn]

That nut will isolate the power feed between battery and starter/alternator.

Their is a small connection to the alternator and the starter but they aren't live with the key off (in fact testing for any voltage on those small wires to starter and alternator would be a good test for parasitic drain).

On the m54, the power cable goes from b+ to starter then to alternator.

When changing the starter, it's at least 4x easier to fit the starter if you disconnect the alternator power lead to get some slack! Store that one away for future use!

I don't disconnect the battery ground when changing alternator or starter I just make sure no key in the ignition. Just remove the B+ jumper nut.

[Millmo]

Originally Posted by petebert

It's the 3.0 and in a weird change of events it seems to have at least temporarily fixed itself. Maybe that's why I didn't find an amp draw the other day.



The battery had been losing about 1 volt every 12 hours. I was going to do more testing so I went out last night to get a voltage reading and it had barely dropped. Did another reading this morning and again the voltage has barely dropped.

Well? Was it the starter?? Very curious...

[wpoll]

Originally Posted by Millmo

Well? Was it the starter?? Very curious...

+1 - do tell.

I'm seeing about 70-80mA draw when asleep - a tad too high but I can live with it if i drive at least every other day etc.

Checked all the usual suspects - no dice. Think it might be the CD Changer or something. Need to test more.

[Millmo]

Originally Posted by wpoll

+1 - do tell.

I'm seeing about 70-80mA draw when asleep - a tad too high but I can live with it if i drive at least every other day etc.

Checked all the usual suspects - no dice. Think it might be the CD Changer or something. Need to test more.

Me too. I'm at .6A and am SO frustrated.

[Bmwe5320023.0]

70-80mA is nothing in my opinion.
.6 amp on the other hand, which is 600mA, would be more concerning. I'd definitely try to find the source.
Just do the procedure described in this thread and find the problem

[petebert]

Originally Posted by Millmo

Well? Was it the starter?? Very curious...

Well I haven't tested anything else yet because there's a new clue. It only loses voltage after in rains and I found out the rear carpets are getting wet.



I did the pour test with the sunroof open and found the front drivers side wasn't draining. Took the A-pillar cover off and the tube wasn't really in the hole. Sadly the carpets are still getting wet and the battery is still draining if it rains. Next thing I want to do is get inside the car and have a kid drench it with a hose.

[FocusArmy]

Fuse 43 5A instrument panel causing drain and preventing sleep.

So given this nightmare issue I joined to present my findings that might help others.

So spent ages chasing down a 0.42 amp drain.

Came to fuse 43 pulled it, and alas drain dropped to 0.02 amp, then after 16 mins gear indicator light went off and it went to sleep.

Any idea what could be causing the drain in the instrument panel?

Are there any coding issues with panel if replaced and is it an difficult job to take it out?

Till then I'm just gonna pull the fuse each time i leave the car overnight.