525i Wagon power drain - .65A

[aslan.de]

Okay, saw a few people on here talking about a similar problem with a nice simple solution. Wish mine was as simple a solution....

I ran my multimeter in series with the battery and discovered that my current draw is .65A. This would explain why the car can't sit for longer than a day without losing a charge. I went through each fuse, checking to see if things changed. Only one lead to a lower draw (.17A) and that was pulling fuse #20. There were also a couple that made the draw go up to 1.4A (fuses 10, 11, 22, 23, and 41) not sure how this is happening.

Any thoughts?

[aslan.de]

Okay, two questions related to this problem:
1) where can I find the chime module? What does it look like? The Bentley Manual says its in the LH footwell. Okay, where exactly does that mean? up near the steering column?

2) The drawings in the Bentley manual and at other locations show that the positive terminal of the battery is connected to a junction. Where can I find this junction? Is it near the terminal itself? (Just trying to understand the drawing as best I can. I was hoping that the whole setup would be under the back seat and I could just start selectively testing the pieces of the electrical system.)

[aslan.de]

Okay, the problem is definitely something attached to fuse #20. Tested again, this time making sure all the doors were closed. Current draw with fuse #20 was .5 A, current draw without was .03 A, or about 30 mA, which is the normal draw.

I made a matrix of the items identified by Bentley's and the items identified by the car as being attached to fuse #20. It does kind of worry me that the two lists aren't exactly identical, but I'll chalk that one up to the fact that my car is German spec. I also checked to see what other fuses were attached to the items in question and whether they were hot or not all the time. My list indicates the following possibilities:

Instrument cluster (Bentley's, fusebox on car) Also uses fuses 1, 17, and 29 which are not hot all the time. Very low probability of this one since I disconnected the instrument cluster during initial testing and it didn't result in a change (still haven't got my steering wheel back on straight).

OBC (Bentley's, fusebox on car) Also uses fuses 1 and 17. Very low probability since I disconnected the OBC during initial testing.

Electronic Throttle Control (Bentley's) also uses fuses 1 and 17. I don't know what this is, help would be appreciated.

CCM (fusebox) Also uses fuse 1. Very low probability since I was able to switch it out with two other units and test with it out of the car.

"Heizungregelung" (translates to "heating regulating", fusebox) Also uses fuse 27. Not sure how to test this one. Any suggestions on how to isolate and test?

"Standheizung, Standluftung" (translate to "parking heating" and "parking ventilation", fusebox) Also use fuse 28, which is not hot all the time. Any suggestions on how I can isolate and test these two features?

That about covers it, although both the Bentley manual and another set of electrical schematics that I found online both indicate that there are a few other components that might also operate off of fuse 20 (like the chine module). I'm also not positive that my logic is spot on in this case as well and would appreciate a check by any of you more experienced gents who might know a bit more about the electrical system of a BMW than I do. The basis of my logic is that if a component has more than one live feed in the off position, than that component is less likely to be the current draw (since in the off position, it would also affect any other live feeds that it is connected to). I also feel that if I can isolate each possible cause in turn, I will eventually, by process of elimination, fall on the fail(ing) component and thereby be able to replace it and (hopefully) eliminate my high current draw and not have to drive the car every day (I'd like to let it sit there a few days a week and carpool).

Any assistance, even if it is "your logic sounds reasonable" or "your logic is crap and here is why" would be appreciated.

[shrike071]

[QUOTE=aslan.de]Okay, two questions related to this problem:
1) where can I find the chime module? What does it look like? The Bentley Manual says its in the LH footwell. Okay, where exactly does that mean? up near the steering column?

Chime module - under the dash, on the drivers side. There is a cluster of computers on the left, near the kickpanel. The chime is usually attached to that cluster. It's a roundish black thing - easily identified as a speaker.