Long (LED?) third brake light, '99 528i, no go

[CQHixi]

All--
First post here, I've looked all over this forum and can't find what's what.
Issue--3rd brake light is a long set of LED-looking lights, not a swap-able bulb. It doesn't light up with the brake, but the others, which ARE normal bulbs, do. Is it on a seperate fuse circuit for some reason? I've ordered and replaced the bulb assembly, still no go. What gives? I should note that there are no dash/console 'error' lights at all.

[milla290]

All--
First post here, I've looked all over this forum and can't find what's what.
Issue--3rd brake light is a long set of LED-looking lights, not a swap-able bulb. It doesn't light up with the brake, but the others, which ARE normal bulbs, do. Is it on a seperate fuse circuit for some reason? I've ordered and replaced the bulb assembly, still no go. What gives? I should note that there are no dash/console 'error' lights at all.

Really! ? Mine is an incandescent bulb....

[CQHixi]

Update--
So I started tracking the wires back and found that the black wire with the yellow stripe was actually broken--looks like it had corroded inside the square rubber boot that extends from under the left rear ceiling upholstry. Spliced the wire back together and good to go.
Yes, the light was weird. BMW part number 63 25 8 362 297. BTW, a new light was over $200, found one at Bavarian Auto Recycling for just about $90, with shipping. Now if I can only convince them to take the light back!

[ithaca]

I took my car in for NYS annual inspection not expecting any issues. I get a call at the end of the day saying that my third brake light is not working. I declined the $400 offer to fix it. I saw that Pelican has the assembly for $251 for the touring, so maybe that quote wasn't too far off. I'm going to inspect mine this afternoon. Thanks for the post.

[Mac Castle]

Does anybody know how to replace the third light housing? I know I gotta take the back seats and rear panel off but no DIY(sorry hope my question relates to op)

[97heath528i]

There is a DIY maybe not specific to the third light, but putting in rear speakers would mean doing the same things to get to that same area. That would give you access to the third brake light.

[CWB]

mine is an easily changed $1 bulb...

[ElleShooTiger]

I think you guys need to specify what car you have, sedan or touring. The sedan just has a simple bulb, the touring has the LEDs I believe.

[ithaca]

so here is the LED strip that is not working.


and I guess that I could access the wiring by pulling the immediate liner off here, but this what I see....WTF?? Am I going in the right direction? And is what I'm seeing to be expected? melted rubber lining?


Before I go tearing into this any further- I'm not getting a warning light that the center brake light is out....shouldn't I be getting one? how to interpret? thanks in advance

[tbass]

Update--
So I started tracking the wires back and found that the black wire with the yellow stripe was actually broken--looks like it had corroded inside the square rubber boot that extends from under the left rear ceiling upholstry. Spliced the wire back together and good to go.
Yes, the light was weird. BMW part number 63 25 8 362 297. BTW, a new light was over $200, found one at Bavarian Auto Recycling for just about $90, with shipping. Now if I can only convince them to take the light back!

Hixi, do you still have the third brake light for the touring? Is it new? mine has a few LEDs that are dim. I would be willing to make you an offer.

[Mainfold]

so here is the LED strip that is not working.


and I guess that I could access the wiring by pulling the immediate liner off here, but this what I see....WTF?? Am I going in the right direction? And is what I'm seeing to be expected? melted rubber lining?


Before I go tearing into this any further- I'm not getting a warning light that the center brake light is out....shouldn't I be getting one? how to interpret? thanks in advance

A bit late as this is from like 2009 and whatnot.. but did you ever find a solution to this?
I've been looking like crazy for any form of guides on how to do this, but seems like there's nothing to find, and all the BMW manuals only say to bring it to the dealership to get the wagon's led third brake/stop light fixed.

I pulled it apart, but the wire leading from the led light just seemingly is lodged onto something in the slit it goes into, and I have no idea where to go from there. Pulled off that panel and there was like a rubber-boot with wiring stuff going into the glass-lid part of the trunk, which I assume the wiring to the third light goes through, but never found a way to get it out to check, if there even is a way to check it from there or see where it even plugs into.

I'm running out of ideas and I have about 2 weeks to have it fixed or it will fail inspection.

[StephenVA]

Wagon Application
I am have the same issue. Pull the LED light tested it with a 9 Volt battery, works perfect. Checked the wiring and have found nothing so far. Have not gone any further so far so I am interested in what you find.

[Mainfold]

Hahaha I did the EXACT same thing today. It's all designed by BMW like they want to not make it possible to do without cutting the welds to gain access to wherever there may be a break in the wires.

I was considering there may be some problem wherever the third brake-light meets the others, maybe it's the brake light switch, maybe somewhere else.. no idea where it could be without tracing the whole system (as it seems to be lacking wiring-diagrams for it).

I'm gonna do a temporary (may end up being permanent) fix for it myself, as the led light works, I'm gonna pull wires from the led light down through the boot, behind the plastic hinge-covers and down underneath the plastic panels, down to the left-side brake-light and splice it in there.

I might take pictures of it when I do it if I can remember to.

[f355spider]

Hahaha I did the EXACT same thing today. It's all designed by BMW like they want to not make it possible to do without cutting the welds to gain access to wherever there may be a break in the wires.

I was considering there may be some problem wherever the third brake-light meets the others, maybe it's the brake light switch, maybe somewhere else.. no idea where it could be without tracing the whole system (as it seems to be lacking wiring-diagrams for it).

I'm gonna do a temporary (may end up being permanent) fix for it myself, as the led light works, I'm gonna pull wires from the led light down through the boot, behind the plastic hinge-covers and down underneath the plastic panels, down to the left-side brake-light and splice it in there.

I might take pictures of it when I do it if I can remember to.

I would try to mate the wires back up with the original wiring if you can find where it is. The problem with splicing into one of the other brake lights is it will play havoc with the light control module and probably display a bulb out warning or not display a bulb out warning when the left brake light is out.

[Mainfold]

I would try to mate the wires back up with the original wiring if you can find where it is. The problem with splicing into one of the other brake lights is it will play havoc with the light control module and probably display a bulb out warning or not display a bulb out warning when the left brake light is out.

In theory it shouldn't do that, as the LED light itself doesn't actually have anything that it can trigger as "light out", and seemingly then it requires so much less voltage to run (hence it being LED) that you can power it with a 9V battery or lower, which shouldn't really do anything to the bulb-light when it's only "backpacking" off of the wires going to the normal bulb-light. They'd both be receiving the same amount of power.
If it was a case of pass-through, yes then I would assume it'd cause errors possibly, but as it's just essentially like plugging it in parallell and not serial it shouldn't affect it like as if was a new source of resistance etc.


I'm gonna test it out obviously, before I route the wires behind lots of panels etc.
But when it came to looking at the wires leading all the way from the plug of the LED light down to where the wires end into the roof-section (the hole next to the hinge), I couldn't find anything that looked like any damaged wire from what I could see (and from what I've seen in pictures from folks that had wire breaks somewhere down that line, it's always been in the spots where there's movements in the wires like the hinge areas etc..), so I assume it's past that point that there's something going on.

I did have a theory that it might be somewhere between where they enter the hole into the roof-section and the brake-pedal light-switch, but how on earth would one even go about troubleshooting such if it's in the roof?
Do the wires pass by (like on the E60's) one of the rear roof-mounted speakers? If so, that might be worth a check, but wiring diagrams for anything remotely related to the LED light are apparently impossible to find. I did find a wiring-diagram from BMW, but the section where the LED light would/should have been, all it said was something like "Please contact a BMW center in case of LED strip malfunction.". The more I work on the E39, the more it's going from my favorite BMW to my most hated BMW.

[Mainfold]

Update to my little "project" of wiring the LED-light to the side stoplight.. LED wouldn't light from being tapped into the same wires as the stoplight part of the left taillight.

All that happened was that somehow the stoplight-bulb blew (swapped it for another and it worked like before), so I have a feeling that there's more resistance in the bulbs than the LED-array, and when adding a source that has a different amperage and resistance, it changes up the amperage to the bulb as well (when it encounters lower resistance in the LED-light). Something quite a bit lower than 2.5Ω I would assume (maybe 15A or even more if the resistance is just super low on the LED-light).

Anyone have any other ideas as to where it could be hooked onto to get the third (LED) light working along with the other two when braking? I'm out of ideas that don't require troubleshooting the entire wiring from the connector of the LED-light back to wherever it ends at (as the light itself still works and lights up with even a small battery).

[David60]

Hey Mainfold, can you think back to 2018? Did you find a solution? I have the same problem as you (LED strip not working - other lights do) and am stumped. Wires at the hinge look OK, so I'm wondering what to do next.

[David60]

Never mind, problem fixed. I found the LED strip was water damaged, so replaced it with a general purpose LED strip from an electronics shop. The casing of the light unit is not meant to be opened but can be.