Brake lights don't work?!?

[DesktopDave]

So I figured out how to pull the brake switch.  You have to hold the  brake pedal down, then pull the brake switch post out (toward the firewall) a little bit.   Feels like it'll break, but it didn't.  Then slide the inner locking collar all  the way forward.  Finally, pinch or press in the tangs on top & bottom of the brake switch housing,  and wiggle it out.

As annoying as this one was, I figured I'd post the solution.

I noted that while I was driving my 3rd brake light wasn't working.  Sure, easy fix...burned out light.  Replaced it, didn't think about it until I was driving again at night.

Guess what?  No 3rd brake light!  Stupid thing...maybe a wire chafed or shorted.  Whipped out the DMM, checked the fuses for anything smoked, got the kids to watch the regular brake lights.

So my son tells me that the lights are always on.  Can't be...I'd have seen that for sure.  What he meant to say was "With the sunlight reflecting off the brake lights they look like they're on."  Can't trust a six-year-old for anything, can you? So I decide to finally start using my brain.

Here's a good bit of advice: carry a short length of wire with you at all times.  I have a few foot-long bits that are stripped just for testing & jumpering & resetting the oil lights.

So I grab my little length of wire, pull the brake switch connector & short it with a bit of wire.  Brake lights work!  Wiring & fuses eliminated as a cause.

Next, I test the continuity of the brake switch.  Tests perfectly.  I pull the taillight panel and leave it on the trunk rim (so I can see it from the driver's seat) and plug it all back together. No lights.  WTF?

 The cause of my trouble was immediately apparent.  The rear plastic  cover has cracked, keeping the switch apart and preventing the brake  lights from switching on.

So I went to my spare car, pulled a switch, tested it first, then installed it.  Problem solved.

[YetiX]

When I got my car the brake lights didn't work. After checking the fuses and the bulbs I remembered having a similar problem on a motorcycle and it being the switch. I checked the switch on my 318 and it crumbled in my hand!!

Drove the motorcycle to a friend with a parts car and learned there are two different brake switches. D'oh!!!

Moral of the story, take your switch to the dealer to make sure you get the right one. I bought a spare just in case.

[dude8383]

Before you do any of that, pull the brake switch it out, its just behind the brake pedal.

There's a red "ring" around the switch, you should be able to pull it out (the red ring) and more or less reset it.

Give that a shot before you spend the $15-20!

http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=35_0183&hg=35&fg=05

# 6

[DesktopDave]

I could likely repair the old switch with a touch of plastic epoxy.  The rear case cracked & one of the ears is letting the button stick most of the time.

I fixed my cruise control today too, and found a bunch of bolts I'd lost from the driver's knee bolster.

AND I got to work pretty much all day on the car...I'm on a roll!  Next is getting those damn steel wheels unstuck, swapping for a decent set of bottlecaps, a rear bearing & CV boot and the passenger parking brake. And eliminating any rust I find.  I'll be done by next year at this pace.

So more how-to's to come...this Labor Day weekend is for the cars.  I'll have to get those engines swapped & do a few test drives.

[dude8383]

PB Blaster is your friend! If anything grab a torch heat up the area around the hub.