Tach, odometer, radio, obc, interior lights suddenly not working.

[Animefrank]

So start off it stormed bad the other day and the morning after, driver side floor is harboring water. A ton of water. However all the electronics still worked and I drove the car all day. The next day is when everything the topic says went out. Fuses are fine. Checked all possible wiring all fine. Replaced all fuses. Nothing I'm going mad and the car is driving me up the wall. Help me with this please

[Animefrank]

Everything but the odometer tach and economy works on the cluster, obc lights up but displays nothing. Flashlight charger is clear of debris. And I'm about to take the driver seat out and carpet next. I just don't understand why if the water on the drivers side floor is the issue why didn't it start that day and why wait till after cleaned up and dry the next day for this to happen.

[Gregs///M]

Dead SI board batteries, probably not related to the rain but related to removing the fuses 10, 12 or 21. When batteries are near death, any removal of power can cause them to drain to the point where they will not recover. If your SI batteries have never been replaced they are near 25 years old and surely dead.

The SI board powers and controls signal for the tach, temp, and MPG and OBC. Odometer is a very common failure but its mechanically connected to the speedometer. So if your speedometer and odometer fail, its probably a fuse or sender problem. HOwever if your speedo works and odometer does not, its definitely broken odometer gears.

[Animefrank]

Tach, odometer, radio, obc, interior lights suddenly not working.

Well the fuses were fine to begin with only reason why I replaced them was because they looked old and trying to figure out why nothing is working. I read if the si board is dead then the service lights wouldn't work as well? Still doesn't explain why out of nowhere these things especially the radio and done lights to have stopped working.
Also the speedo works but the odometer isn't. Plus all lights work like obc back light and instrument lights, service indicator etc.


I've back tracked majority of almost all wiring and cleaned the connections with still no luck. I have noticed that every other time I turn the key for power my check overhead shows that wiper fluid, coolant and oil is low like a reset? I feel there is a hidden power wire or fuse somewhere that isn't giving power to these things and I just can't locate it.

[chuck90m3]

I have the same problem with my car. I've taken a cluster that was verified to work correctly in two different e30s and my odo will not work when installed in my car. Odo gears are good and EVERYTHING else works properly in both of the other cars.

[Animefrank]

I have tracked down why the radio doesn't work. There is no power from the memory wire which is yellow from radio to grey/red (can't remember if red or green) the fuses are still fine and none are blown. The overhead check panel is still acting like how after the battery is disconnected and reconnected resetting everything. Now the brake lights on the panel are sometimes not going off when pressing down the pedal.

[Gregs///M]

Well the fuses were fine to begin with only reason why I replaced them was because they looked old and trying to figure out why nothing is working. I read if the si board is dead then the service lights wouldn't work as well? Still doesn't explain why out of nowhere these things especially the radio and done lights to have stopped working.
Also the speedo works but the odometer isn't. Plus all lights work like obc back light and instrument lights, service indicator etc.


I've back tracked majority of almost all wiring and cleaned the connections with still no luck. I have noticed that every other time I turn the key for power my check overhead shows that wiper fluid, coolant and oil is low like a reset? I feel there is a hidden power wire or fuse somewhere that isn't giving power to these things and I just can't locate it.

The service lights can remain on even though the SI batteries are dead. In fact, in many cases, the SI batteries die and the service lights never shut off, even with the key out, leading to draining the starting battery.

if your speedo works and your odo does not, the gears have failed or jammed.

[Animefrank]

Alright was able to fix the problem. Where the dead pedal is behind the carpet is a bunch of wires that run down to the driver side floor wall that leads to the back. Literally behind and next to the dead pedal carpet is where I found all the wiring to the tach,obc,etc had corroded and broken apart from the clamp. Properly fixed it and everything returned to normal. Hope this helps future searches.

[Bullhead]

I am having this same problem but all my wiring is good the car has never been wet inside and all the fuses are good. I am going to say I need to change those batteries you guys are talking about. I am new to BMW's but not new to knuckle busting, is this pretty easy on the soldering? And in the link provided it says make sure the batteries are charged. Do they not come charged and do I have to buy a charger for 2 batteries I will never prob need again lol?

[Bullhead]

I found this right up and it seems pretty thorough, I did find a good post here in the diy of taking the instrument cluster out with pics. Here is the link for the battery replacement. http://www.pelicanparts.com/BMW/tech..._batteries.htm