Strange Dash / OBC Problem

[cory58]

I posted this in the stereo/electronics section last month and didn't get any repsonses, so I'm hoping this forum might get better results:

Some of the lights on the dash of my 92 325iC stopped working yesterday, and I'm hoping the collective wisdom of the forum can point me in the right direction.

The following lights no longer illuminate when the car is running (1) service indicator lights, (2) e-brake light when the e-brake is engaged, (3) OBC light. Everything on the dash looks fine when the key is in the "on" position without the car running, except the OBC light, which still doesn't work.

This doesn't seem like a fuse or relay, since everything lights up (except the OBC) when the car is not running. To my knowledge, all the lights worked correctly until yesterday. Any thoughts would be greatly appreciated.

Thanks, Cory

[jlevie]

Could be burned out bulbs...

[Jordan325iC]

This happened to me, except my tach died (my gauge lights stopped working a long time ago). This time the tachometer/mpg gauge/temp gauge stopped working, along with the OBC power (it's actually a gauge now, but it draws from the OBC power and doesn't light up anymore).

I am at a loss. I think the gauge cluster and the OBC are fairly interconnected. I'm going to replace my gauge cluster (w/ new SI board) and see if that helps.

[cory58]

Well, now there is a new problem added to the list in my original post. My odometer and trip meter are also not working. I checked fuses and all are good. Looks like I will be removing the gauge cluster. Should I be thinking about replacing the pc card/batteries in the cluster?

Thanks, Cory

[jlevie]

This last problem is likely to be the odometer gears.

[E30_fiend]

The obc not lighting up is definately the lights. If you're unsure, get a flash light and shine it directly on the obc screen and see if there are any numbers or letters visible. If there are then its the light bar that's burned out, if not then its the obc itself.

The odo not working is probably the gears.

And the e-brake light not working is most likely the cable connection. To test this, take the e-brake boot off and you will see a cable on the bottom back side IIRC, this has been known to slip off of the bracket which makes a bad circut.

And the service light, they don't work at all? Even when the car isn't running with just the key on? If that's the case then its your si board batteries. Easy fix.

So check those things out and let us know.

Hope that helps a little.


E30Fiend

[cory58]

Thanks for the responses! I will check the odo gear and e-brake wiring and report back to the forum.

e30 Fiend - all the lights on the dash work, including the service and e-brake lights, when the key is in the "on" position with the car not running. When the car is running, the service and e-brake lights do not work.

Thanks again, Cory

[Jordan325iC]

This happened to me, except my tach died (my gauge lights stopped working a long time ago). This time the tachometer/mpg gauge/temp gauge stopped working, along with the OBC power (it's actually a gauge now, but it draws from the OBC power and doesn't light up anymore).

I am at a loss. I think the gauge cluster and the OBC are fairly interconnected. I'm going to replace my gauge cluster (w/ new SI board) and see if that helps.

It ended up being a bad SI board, like I suspected. I'm not sure exactly why the OBC and the gauge cluster are connected like that, but apparently they are. I replaced the cluster with a working one and my problems were solved.