3rd Brake Light Always On

[PettitWC]

Hey my 3rd brake light (the one at the top of the rear glass) is always on now. I'm not sure how long it's been doing this but it seems kind of weird to me. I'm also not sure what might have caused it as I don't know when it started doing this. It seems to be on the same line as the tail lights because when I actually apply pressure to the brake pedal the 3rd brake light gets brighter as the tail lights do.

any help is much appreciated

thanks,
chris

[mooseheadm5]

Think you may have a short in your harness in or leading to the hatch, or a bad ground backfeeding through that light. Carefully inspect wiring and report back.

[PettitWC]

sorry to bring up an older thread but I'm still having this problem but I've noticed it's more wide spread than just the third brake light. I have looked at the wires around the brake light and did not notice anything.
All of my brake lights are on all the time when my headlights are on. When I brake they get brighter but they are still on all the time like they were just extra parking lights. Also, my right hand side front turn signal is always on and acts like a brake light (gets brighter when I press on the brakes, even when the lights are off). My radio has also somehow managed to get in on the fun. Even if the key is not in the car and I have the headlight switch on and my foot on the brakes, the radio turns on.

Does anyone have any ideas? Brake light switch maybe?

i also just replaced the headlight switch if that would have anything to do with it

[pnosker]

Wow, that is pretty weird. I doubt it's the brake light switch but it definitely sounds like a harness issue. Perhaps a mouse or something got in and nibbled at some of the wiring? Since the front turn signal is screwed up, it's probably near where that wire separates off of the harness.

[cooljess76]

I was reading in here a few months ago and fornd that there's a wire bundle going to the hatch that tends to get frayed and causes all sorts of electrical problems. I wonder if this might be the issue. You might try to cut some of the insulation away from the wire loom where it goes back to the hatch and check to see that those wires haven't worn through and shorted out.

[318iS]

Originally Posted by cooljess76

I was reading in here a few months ago and fornd that there's a wire bundle going to the hatch that tends to get frayed and causes all sorts of electrical problems. I wonder if this might be the issue. You might try to cut some of the insulation away from the wire loom where it goes back to the hatch and check to see that those wires haven't worn through and shorted out.

i was going to say the exact thing....


but i taught this was only an issue with a coupe cos of where the wiring is located ?

[PettitWC]

is that just in front of the hinges under the headliner?

[318iS]

heres the full bimmerforums write up....

http://forums.bimmerforums.com/forum...ad.php?t=79896

[cooljess76]

I can't believe you found that thread! For some reason, I thought it was an issue with the Ti's. Didn't realize it was on the other forum. Anyway, good bit of info. Wouldn't hurt to check things out just as a precaution. Did you read, that guys car caught on fire!

[PettitWC]

awesome man, thanks

[PettitWC]

oh no way, my cruise control hasn't been working either but I always drive with my lights ojn. I'll have to check that out. thanks. I think I'm gonna take it to a shop b/c i don't have enough time to go through all the wires and re-wrap them and everything. the cruise control seems like a related issue with the lights. I'm not quite sure how my front end got in on it too but whatever.

[PettitWC]

no, I haven't had a chance to do anything yet. I think I'll just take it to a shop when I get a chance.

[PHL]

High mount brake light is always on, along with the brake light with the dual filament bulbs at the corners. Replaced two blown bulbs on the high mount, but the lights remain lit. Checked and reseated all the bulbs numerous times--no luck. Fuse 46 is good, even swapped it just to make sure. The wiring seems okay. Just a simple visual inspection, nothing seems loose or out of the ordinary.

Am I dealing with the brake light switch? Stomping on the brake pedal doesn't make the lights flicker as in the first post.

[PHL]

Follow-up to my post above. Turns out the bracket off the clutch pedal that has the tab the plunger from the brake light switch engages had slipped (sorry, super confusing).

http://www.realoem.com/bmw/showparts...52&hg=35&fg=05

Loosened a 10mm bolt near the slave cylinder, adjusted said bracket, and everything worked. Of course, I found this out only after tearing apart a functioning brake light switch, which is the only piece on non-brittle plastic in this whole car.