Overhead Check Panel Question

[1SGDHORN]

My Brake light bulb out warning light is constantly lit on my overhead check panel yet I don't have a brake light that is out. Will this light also light up if there is an issue with one of the brake pad sensors? Just trying to figure out why or what is triggering this to come on???

[aaverhulst]

No, the brake pad wear sensor is different, you'll find that out one day. I had the same issue you did long time ago, I think I removed the brake light one at a time, cleaned them and firmly reinserted. That fixed it. If that doesn't do it, take 1 bulb out at a time and replace with a new. Maybe that will fix it. If not black tape is your friend. I really, really despise BMW warning sensors!

[richardodn]

Did you check the high brake light? Is this the convertible?

[1SGDHORN]

Not a vert, it's my 86 325e. The third brake light works fine. I'll try removing, cleaning and reinstalling my bulbs.

[superj]

also, the sensor are made to read resistance off the lights that have a silver base, not the brass base bulbs. those will make the light come on constantly

[1SGDHORN]

That's good to know. I will have to look and see what type of bulbs I have.

[1SGDHORN]

I was so hopeful when I checked the bulbs and found one was the brass base vs the silver base. My hopes were quickly dashed when I changed it out for a silver based bulb and the overhead brake light out indictor was still lit. On the bright side, all the brake lights work at least. And yes, I even checked the third brake light bulb.

Could it be an issue with the check panel itself?

[richardodn]

Not likely. The way it detects a burned out light is as follows. The sensor "relay" for each lighting circuit is a coil wrapped around a reed switch. If enough current is running through the wires, a big enough magnetic field is generated to flip the reed switch on. In the case of the brake lights, you have one in the high stop light housing and one for each brake light inside the check relay. These are all in series. If these 3 switches don't turn on when the check control sees the brake pedal pressed, it sets the light.

Now if enough current is not flowing, one of the reed switches won't close. Now if you know ohm's law (E=I*R or I=E/R) then you know as resistance goes up, current goes down. So basically if there is too much resistance in any of those location your check panel will light. Check all your bulbs again. It might be a good idea to simply replace them all including the high brake light. The reason I asked about the convertible is a known issue with the high brake light's circuit board. There's a similar circuit in the regular cars. Make sure the connectors aren't corroded.

[sienayr]

The brake switch is also worth checking.

https://www.r3vlimited.com/board/sho...d.php?t=260144

Also check the grounds back there, ground points can become corroded and cause false warning lights.

I had a bulb that still worked, but it must have had a loose filament because it was randomly tripping the panel light. Of course replacing all bulbs would fix that.

Good luck.

[1SGDHORN]

All new bulbs didn't fix the issue. I will be checking the brake switch next or maybe just replacing it.

[superj]

that's weird. it sounds like you might have a larger issue. I guess we will see how that switch goes

[M4R71N30]

Hi all,
My over head panel doesn't light up or work. How can I fix this?

Cheers

[aaverhulst]

Count your blessings. I can't think of any info that panel gives that is useful, or you can't find out in a practical manor. You get many false reading you chase your tail trying to find out why the sensor is giving you a warning. On an old car, you should checking for these things on a regular basis.

[superj]

Thats true. It looks cool but is all stuff that should be checked regularly anyways

[323i E30]

I like it
Checking my overhead panel is so much lazier and quicker than having to check things outside of the car, and it has always been accurate on all of my E30s (except for my oil light with this one, since the engine swap).
A light that will warn you of your oil level being at minimum is without a doubt a useful feature though.
Yes, you should check it regularly, but not everyone always does so.

[DanZ3]

I know the OP car isn’t a vert but I had to replace the small circuit board in the third brake light. I replaced it with the one from a non-vert and now the sensor works fine. On when started and off after touching the brake.

[georgiaboy]

My comment probably won’t be very helpful, but I will state it for the sake of covering all the bases.

The cover for your lights located in the trunk has to be tightened down properly or it could trigger the sensor on your overhead panel. As I drive my vehicle, it occasionally works loose and my panel triggers a light problem, but when I tighten the cover the warning is removed from the panel.

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