Battery Drain fuse 21

[brads2002]

Hi Folks,

I am getting .11 draw on fuse 21 which is going to be a pain to trace because it is almost everything that lives in the dash. Its killing my battery within a week. I did a search and this draw seems pretty high. I checked my 318is and its drawing .01 which seems right. Anyone had this issue before? I am hoping for some direction before pulling the dash all apart. When fuse 21 is pulled it reads the same as the 318is. All factory electronics in the car.

I don't think its the door lock thing, it isn't hot and i don't think they are on fuse 21.

Thanks

[Johnnypix]

Wiring diagram

There are wiring diagrams on this site just take a look at page
21 it has a picture and list of the items used by fuse 21.
I think it might be the trunk light or glove box light.

http://shark.armchair.mb.ca/~dave/BMW/e30/e30m3_88.pdf

[brads2002]

Thanks for the link to that site. That is getting printed out for the manual shelf.
I checked both the light in the trunk and the glove box and they seem to be shutting off. I pulled the little flashlight in the glove box too but that didn't change things.

[brads2002]

This seems almost too good to be true but apparently it was the chime. I figured i was going to have to pull out the cluster and started to attack it. After dropping the kick panel I pulled the wires to the chime.

Chime plugged in .11
Chime unplugged .01

I never noticed it but the thing didn't ring anyways.

Best part about this is it was the most useless part on that circuit! I don't have to replace anything.

Thanks again for the diagram.

[UweM3]

This seems almost too good to be true but apparently it was the chime. I figured i was going to have to pull out the cluster and started to attack it. After dropping the kick panel I pulled the wires to the chime.

Chime plugged in .11
Chime unplugged .01

I never noticed it but the thing didn't ring anyways.

Best part about this is it was the most useless part on that circuit! I don't have to replace anything.

Thanks again for the diagram.

you're not replacing the chime? Very important part [peace]

[OZM3]

Can you tell me the 'chime' is.

[brads2002]

Yup-chime module, the thing that bings when you leave your headlights on or keys in the ignition. Its in the kick pannel right above the dead pedal. Looks like a little speaker in a box with 2 sets of wires going into it.

HA! No, i am not going to replace it.

[dllance]

When you're checking the fuses, your checking voltage correct?
When I just checked mine, fuses 4,5,6 and 12 all showed .313v with the key out and everything closed. Can anyone tell me if these should be 0.0v?
Thanks

[dtmdave]

Bumping an old thread. Have a .75 current drain on fuse 21 also (with key out, all doors closed). Checked the following:

1. Disconnected chime, didn't change it.
2. Found a broken wire to trunk light, fixed it, and issue still there (didn't seem to be related to the current drain as the wire was just broken)
3. Pulled the main relay, didn't change it
4. All interior lights are off and seem to be working ok
5. Glove box light only comes on with key in, so with key off should not be the issue.

Any ideas?

[Quest]

I have a battery drain too that I really would like to get around to fixing! Can someone tell me how do you test for a drain??

[dtmdave]

Put a meter in series between the negative battery post and battery clamp. Set it to read current, close trunk so meter is visible. start pulling one fuse at a time and watch to see when the reading drops. On mine it was at .75 then when i pulled fuse 21 it dropped to 0....

[brads2002]

Looks like all this stuff is on that line...Flashlight, Ignition Key and Seatbelt warning, Interior lights,Fuel injection electronics, Radio, Trunk light, Check Control, Service Interval Indicator, OBC, Tachometer / fuel economy gauge

[dtmdave]

Correct. Was thinking it may be the battery in the SI board. Except I was reading that in 6/89 production switched to lithium battery (not the rechargeable NiCad), so not sure if I have the old style ones since the build date was 9/89. Anyone know how to test for bad SI battery without pulling the board out?

[brads2002]

You could unplug the cluster and see if that stops the drain. That may narrow it down. Did you try unplugging the radio? There is always a little consumption there with the memory.

[Gregs///M]

I can confirm that dead SI board batteries will permit the oil service or inspection lights to remain powered on. This will kill your starting battery. If you have never replaced the SI board batteries and have current draw on fuse 21, consider the SI board as one of the primary suspects.