Pesky Brake Light Warning

[Lippy]

Hello,
I just picked up a 1988 BMW 325i convertible about 2 months ago and have been trying to sort out a bunch of small issues. One is the pesky Brake Light warning. I've read a bunch about it and have tried a bunch of the solutions, but can't get it to go off.

I've already tried to:
Replace all the bulbs with new, correct bulbs (including the 3rd brake light).
Replaced the brake light switch.
Cleaned the connections on the brake lights.

Nothing will make the light go off.
As with others, my brakes work well and the brake lights all work.

Does anyone have a real fix for this? Thanks!

[uturn]

Parking brake handle down? Brake fluid topped off? Brake fluid level sensor functioning?

[It's Soda Not Pop]

Mine stays on as well. It used to go off at first. But it's been on for years at this point. I replaced everything as well.

[twright]

The clusters are reputed to cause this problem. Put an ohmeter on the brake light circuit and see if is "open". It is easy to see the traces on the circuit board and follow them.

[Panici]

Which brake light specifically?

There are three(?) in the cluster and one in the check panel.

[Lippy]

Sorry, referring to the brake light in the Check Panel.

[Panici]

Sorry, referring to the brake light in the Check Panel.

I believe you can jump the reed switch in the active check relay, it's been a while since I played with it.

Here is a link with lots of reading if you are interested:
https://e30journey.blogspot.com/2017...ake-light.html
Archive link for future use:
https://web.archive.org/web/20220711...ake-light.html


You can also remove the check panel and twist the LED right off the circuit board (or paint it black for a less destructive option). It won't illuminate when you push the CHECK button, but that's better then it staying on all the time IMO.

[Lippy]

Its more annoying that the "CHECK" light flashes every time I start the car until I press the check button. I don't really want to cover up the problem, I just wish I knew how to fix it.
I'm not great with wiring diagnostics....

[Tzantushka]

Does your check light stop flashing after you put your foot on the brake - but before you press the check panel button?

[Lippy]

Does your check light stop flashing after you put your foot on the brake - but before you press the check panel button?

Unfortunately no. Only if I press the "Check" button on the console above the windshield.

[Panici]

I just wish I knew how to fix it.

I believe you can jump the reed switch in the active check relay

Here is a link with lots of reading if you are interested:
https://e30journey.blogspot.com/2017...ake-light.html
Archive link for future use:
https://web.archive.org/web/20220711...ake-light.html

If you check out that link it explains how to diagnose and bypass the circuit if you like.

[dnguyen1963]

I fixed mine...with a square piece of black electrical tape.

[Mike36]

When I deleted mine, I noticed that the wire from the 3rd brake light to the chassis was torn from where it bends at the trunk hinge. You can bypass the 3rd brake light with a wire to see if that's what's causing the issue.

https://www.r3vlimited.com/board/forum/e30-technical-forums/convertible-technical-discussion/382312-e30-3rd-brake-light-delete-with-check-panel-fix

[cirrusblue]

I've 'fixed' this many times over the years - I've had my car basically 35 years since new - soI feel pretty comfortable with this info.

1) The 3rd brake light housing has a small circuit board inside - due to heat, etc. the solder connections get weak and sometimes when hot or cold or going over bumps it's go on or off. I"ve reflowed the solder on this board a couple times -specifically where the wires connect and where the copper wrapper wires connect to pins. I've fixed a couple for other people this way.

2) Sometimes the bulb housing is corroded more than you think - since the bulb twists in, it's the underside of a pretty small space it makes connection - be sure to really scrap in there and get a good contact surface. I like DEOXIT on these kinds of things, but your milage may vary (not literally - figuratively)

3) Check panel connector dirty - I"ve removed the check panel, and cleaned and reconnected it and that helped a couple times.

So far I've had all these problems but it's been working well for a while.

I"d suggest you try these before something more drastic or pulling out bulbs, etc.might work for you

[Lippy]

I've 'fixed' this many times over the years - I've had my car basically 35 years since new - soI feel pretty comfortable with this info.

1) The 3rd brake light housing has a small circuit board inside - due to heat, etc. the solder connections get weak and sometimes when hot or cold or going over bumps it's go on or off. I"ve reflowed the solder on this board a couple times -specifically where the wires connect and where the copper wrapper wires connect to pins. I've fixed a couple for other people this way.

2) Sometimes the bulb housing is corroded more than you think - since the bulb twists in, it's the underside of a pretty small space it makes connection - be sure to really scrap in there and get a good contact surface. I like DEOXIT on these kinds of things, but your milage may vary (not literally - figuratively)

3) Check panel connector dirty - I"ve removed the check panel, and cleaned and reconnected it and that helped a couple times.

So far I've had all these problems but it's been working well for a while.

I"d suggest you try these before something more drastic or pulling out bulbs, etc.might work for you

Awesome, thanks! I'll give these a try.