Battery drain from gauge cluster

[rzerob]

So I went to start my car today, it has been sitting for a week and the battery was dead. So I jumped it and let it run for a little bit. After it was charged I connected my DMM in series to the battery and I had and amperage draw of 80mA(mili-amps). I know that is too much so I started pulling fuses. After pulling fuse 21 my amperage draw dropped to 20mA. I pulled up my wiring diagram:

http://shark.armchair.mb.ca/~dave/BMW/e30/e30_89.pdf

Interior lights removed both and inspected wiring no change in amperage draw.

No flash light.

Trunk light removed pulled wire all the way out to the loom and traced it up to drivers seat, no fraying or pinching found, no amperage change.

Disconnected chime module, no amperage change.

Removed and disconnected OBC, no amperage change.

Removed and disconnected check panel, no amperage change.

Removed and disconnected radio, no amperage change.

Removed and disconnected gauge cluster, amperage draw dropped from 80mA to 20mA.

So I know my parasitic draw is coming from fuse 21 and after going through the wiring diagram it is pointing to the gauge cluster. I did a little bit of research on the computer and I couldn't find any information or similar circumstances. So now I am getting into solid state. I plan on checking the SI batteries in the morning if they are bad that is more than likely my problem. But from what I am reading bad SI batteries cause you to lose gauges or cause faulty SI operation. All of my gauges work and I have proper SI operation. Is there another part on the gauge cluster that is on the fuse 21 circuit that could be pulling 60mA? Anyone else ever been in a similar situation? Anyone know where I can get new batteries or a rebuilt board? The car is 1991 325i, it has never had this issue before.

[jlevie]

My first suspicion would be the SI board batteries, though a fault in the board is a possibility. The batteries could have high leakage and be drawing excessive current.

[rzerob]

My first suspicion would be the SI board batteries, though a fault in the board is a possibility. The batteries could have high leakage and be drawing excessive current.

That is what I was thinking. I am going to go out to my garage and get the DMM and test their voltage. I thought if they were bad that there was my problem. I am not afraid to solder on solid state but if I go that route I want good batteries. Do you know where to get some? But I am also considering getting the SI board rebuilt/refurbished, any recommendations? Is there a forum member here that does this?

[rzerob]

I just checked the SI batteries. Both are over 3v. I am at a loss, any ideas?

SI board



SI batteries

[rzerob]

So I put my car back together, minus the instrument cluster. I plugged the cluster back in and disconnected each harness until I found the draw. My amperage draw starts when I plug in the blue harness on the back of my cluster. Anything?

[rzerob]

So the blue plug is the C1. I did an available voltage test on all the pins and all of them except one was zero volts. The pin circled in orange had battery voltage. The wire to that pin was red and green.



I updated with some pictures. Anybody have any ideas?

[rzerob]

So I looked at the wiring diagrams and the pin circle in orange is pin 2 rt/gn. Which goes to fuse 21 which is hot at all times, which explains why I was getting battery voltage on that pin when I did an available voltage test on it. It still doesn't explain my parasitic draw except that it is coming from my gauge cluster. I really don't want to replace my gauge cluster it is original and it only has 100,8XX miles on it. Does anybody have any ideas or suggestions?

[AndrewBird]

80mA is almost nothing. It's .08 amp. It would take over a month for an 80mA draw to kill a battery. The 60mA to the cluster is likely the circuit that charges the SI batteries and it is working normally.

I would look into your alternator and determine if it is charging properly. Voltage across the battery should be ~14v with the engine running.

Be sure to charge the battery from dead with a battery charger. Letting the alternator re-charge it from dead will over load it and potentially cause damage.

[rzerob]

So I think I figured it out. My inspection light is on when my car is off and I am assuming that is where the draw is. I am going to take the cluster back out and see if I can see any damage and if that doesn't work I was just going to disconnect that bulb. The lights have to be on a parallel or separate circuit because if they were in a series circuit they would both come on and go out at the same time. So I assume if I remove the load of the circuit it will eliminate the draw. I will update after I get a chance to try it out. I know I just need to have the SI board refurbished but my funds are low right now and if it can wait, then I will let it for now.

80mA is almost nothing. It's .08 amp. It would take over a month for an 80mA draw to kill a battery. The 60mA to the cluster is likely the circuit that charges the SI batteries and it is working normally.

I would look into your alternator and determine if it is charging properly. Voltage across the battery should be ~14v with the engine running.

Be sure to charge the battery from dead with a battery charger. Letting the alternator re-charge it from dead will over load it and potentially cause damage.

From what I have read the normal draw is supposed to be between 20 and 50mA. So it is still a draw I want to address. And after I confirmed the draw, I just disconnect the battery and no draw and the car hasn't gone dead yet. And it has been sitting for three days.

I had confirmed the alternator was operating properly before I started this thread. Because I was assuming that maybe the battery light wasn't working and maybe causing a draw that way. But it's not. The draw is coming from the circuit on fuse 21 and I traced it to the instrument cluster.

I suspected my battery would need replaced soon before I found out about this draw, but I don't want to buy one until this problem is taken care of. Thank you for you suggestion. I can't get much done during the week days.

[Yogawrench]

I'm havin' the same problem you have - the inspection lights on the gauge cluster is lit even without the key in the ignition. Never had this problem before, and my battery is dead.

Can't figure out why the inspection lights are on even when there is no key in the ignition. Any ideas, folks?

[rzerob]

Is your draw coming from the fuse 21 circuit? And also coming from the instrument cluster? I plan on taking my instrument cluster back out tomorrow or Thursday. I will update on here what I find and if my idea works.

What I am planning to do isn't fixing the problem. The problem is the SI board, which I suspect is your problem as well. There is a forum member here who I found after some research, refurbishes SI boards. His user name is Gregs///M. Search for it, you will find him.

I plan on getting mine refurbished after I get some money but I would like to address the problem now even if it is just a band aid until I can do it right. And I don't want to have to disconnect my car every time I park it.

[rzerob]

So I removed the bulb for the inspection light and I still had the draw. I pulled the whole light board and I still had the draw. So I put the bulb back in and soldered it and put it back together. I will have to continue to disconnect the battery when I park it until I can afford a refurbished SI board.