For Anyone Doing the Brake Light Switch Replacement

[DYL]

I almost read this too late. I snapped the switch into a dozen pieces and finally got it out before I saw this. Helped immensely with getting the new one in. Also, the switch only goes in one way, round side of the connector towards the floor. You can see the tab on the switch and the cutout in the bracket.

[DasHorse]

Thanks for all the great tips. What worked best for me was the "mirror technique." (I'm 6'5", so let's just say sitting upside down on the seat with my head and arms tangled under the dash didn't work so well.) With the mirror, I just had to overcome being spastic in working backwards. No contortions of the body necessary.

It helps a bunch to have the car running for the assist in depressing the brake pedal.

I accidentally found that when using a screwdriver to extend the white button and red retaining ring, prying sideways on the ring broke it loose and the switch just fell out.

[gmak]

Ummmmm. Undo the clip holding the brake pedal, take off the lever from the brake booster,l and then you can move the pedal easily.

[mdeep1]

Chances are if your OBC is telling you you have a "Brake Light Circuit Failure", but your brake lights are working just fine, your switch has gone bad.

There is a very good DIY on bimmerdiy.com
http://www.pelicanparts.com/BMW/tech...ake_Switch.htm
except for one major mistake.

DO NOT try to just yank the switch out of the bracket, or to break the housing for the switch. The plastic housing is actually far stronger than the tin metal bracket, and you will most likely(as I did) mangle your metal bracket. Instead, depress the brake pedal, slide the red collar forwards, and depress the tabs holding the switch in place. It comes out pretty easy, and you save yourself the hassle of bending the bracket back into the correct position.

Thanks for the tip. It was a big help when replacing the switch today.

this is a relatively easy task as long as you have patience & correct tools.

1. after removing underdash covers, locate the brake light switch which is directly in front of brake (you will see the red tubular sleeve)
I used a headlight (like a coal miner) that I use when duck hunting in dark...you will need light in the area working.
2. unhook the 4 pin connector by lifting the small black hinges on the side & pull off of brake switch
3. you must have someone sitting in the seat pushing the brake hard to give you room to work......if you start engine, it will help the brake to push farther.
4. do not yank switch out with pliers as you may bend the bracket.....I took a hand 6" saw while laying head underneath dash looking up on back with feet over seat in the farthest back position.
5. cut slowly through switch by bracket until it breaks....just make sure you don't cut through anything but the plastic switch...it will eventually loosen & break apart....pull it out of there
6. put new switch in the same way it was situated...(the rounded end down, square end up on the end where the 4 pin connector attaches)
make sure the white plunger & red tube sleeve are pulled all the way out.
7. it is extremely difficult to just push switch straight in......I found if you put switch in tilted a little to the side & then snap it sideways a little it will pop in.
8. reconnect the 4 pin connector
9. it took me about 3 hours

This is the method I used. I couldn't get the old switch out no matter what I tried so in the end I used the saw on my Leatherman to cut the switch. The new switch needs to go in at an angle and it will lock right in.

Thought I would bump this thread since most other diys aren't as detailed.

[JDStrickland]

It's actually pretty easy to just take the seat out and lay on your back on the floor of the car. There is a single 10mm nut that holds the bracket on, and you can bring the whole thing down where you can see it easily. When you put the assembly back in, thera red collar on each of the switches (assuming you have a clutch pedal) that you pull all of the way out. They will self-adjust the first time you press the pedal.

DO NOT TURN THE KEY ON TO TEST BEFORE YOU PUT THE SEAT BACK IN ELSE YOU WILL TRIP AN AIRBAG FAULT.

[E36328Coupe]

Making life much harder than needed, recline seat.

http://www.bimmerforums.com/forum/sh...6#post28368906

~

For points 5 and 6 I pushed the red collar all the way forwards and use self grip wrench to crush the switch / tabs in as scrap

[mdeep1]

It's actually pretty easy to just take the seat out and lay on your back on the floor of the car. There is a single 10mm nut that holds the bracket on, and you can bring the whole thing down where you can see it easily. When you put the assembly back in, thera red collar on each of the switches (assuming you have a clutch pedal) that you pull all of the way out. They will self-adjust the first time you press the pedal.

DO NOT TURN THE KEY ON TO TEST BEFORE YOU PUT THE SEAT BACK IN ELSE YOU WILL TRIP AN AIRBAG FAULT.

It takes longer to remove the seat and 10mm bolt than it does to remove the brake switch. Easiest way to remove the switch is to break one locking clamp on the switch and it will slide out. I used a saw to remove the lock clamp/whatever it's called

[MorfM3]

Thought I'd add my 2 cents for anyone doing this for the first time. I tried for about an hour to remove the switch without breaking it to no avail. I had the car on and depressed the brake pedal as far as it would go, then held it in place with a wire tie. No one mentioned about the air directional unit being in the way, plus, mine is a manual, so you have the clutch to get around as well. All that said, the biggest problem was that I could not get the tabs to depress....and in North Carolina this time of year, it's hot....which means you'll get hot too! I finally took the pliers and twisted the red collar until it broke, out came the switch, in went the new one and on went the plug. Putting it in took all of a minute...and I used dielectric grease on the plug. Next time, I will not bother with any of the 'don't break it' attempts. Far too much trouble for something that's broken anyway. Tie the brake pedal back, pull the red collar out as far as you can, grip it with the pliers and twist until you break it. Be careful not to louse up the bracket, so don't pry, just squeeze and snap it. You'll be done in nothing flat and wonder what all the fuss was about in the threads and you'll retain your sanity. Oh, and I'm a size 46 at 225 pounds, so there's no good position
to be in while doing this....another reason for getting it done quickly. Good fortune to you all.
Scott.

[boarder2k7]

Thanks for sharing! A helpful first post. Stick around, we need more like you...

[adavey32]

Just an FYI - I found this video most helpful, need to be fully inverted, with feet at the head of your seat, with your head on the brake pedal & clutch at some stages, so prepare to have a sore head for a day or two like I did.
https://www.youtube.com/watch?v=2pJEPZstspE
Cheers,

[Edrich]

Thanks for all the notes on this subject. It helped with the install even though I had to resort to the break the switch method. Now, I have the new switch installed but the brakes lights are on all the time. What the heck? Ed

[shogun]

@Edrich: are you talking about E36? Your profile shows: My Cars: A3, A6, 1800E
Does the new switch have the same dimensions as the original one? A wrenching buddy had that problem on his E36, ordered a cheapo brake light switch (shown with same p/n as BMW) but actually the dimensions were not exactly the same, so the brake lights were always on, so he bought a good quality one and no problem.

[E36 Em Tree]

Theres also a 4 pin and 2(?) pin version.. theres two versions.

Also, i vaguely remember changing mine and theres a white plastic lock type thing that you need to pull out or press in for the install. It could be that your button is continuously depressed is what I'm getting at. Especially if you resorted to breaking the switch. Mine took a while to get out, while upside down, seat reclined and kickplate removed. It was hard to depress the brake with my head, and then use both hands to extract the little part

[MParallel]

Can be red or white. White collar is early production. 2 vs 4 pins. 4 is for cars with check control.

The switch can easily be taken out without breaking it or ripping out with a monkey wrench. You just pull the locking collar back out so the two tabs cab be push in to release it.

The infamous "Brake Circuit Failure" that the check control version gives, is just weird, It's a check control for a check control. It's saying it can no longer check, but the brake lights itself work just fine,

I have examined a switch in the past that threw the error. Inside is nothing but thick copper tracks. Nothing that can break really. I cleaned the tracks and bend back some of the 'spring' contacts and it worked fine again.

Tip: the bracket for the switch is bolted on with a single 10mm bolt. Undo this to take the bracket out with the switch. Then it's a breeze to remove it (pull collar, push in tabs).

[E36 Em Tree]

But you also kind of need two hands to wiggle it loose and then the brake also has to be depressed or else it pushes the connector/button on the circuit back in... so i had to use my head to depress the brake pedal while using a little pick tool to gently wiggle the circuit out. It's definitely an easy task made harder by weird angles and space.

[hexdump]

But you also kind of need two hands to wiggle it loose and then the brake also has to be depressed or else it pushes the connector/button on the circuit back in... so i had to use my head to depress the brake pedal while using a little pick tool to gently wiggle the circuit out. It's definitely an easy task made harder by weird angles and space.

I also used my head to depress the brake pedal and ended up with a cut from one of the exposed trim screws. Agreed, not a fun job due to the angles involved. Much worse if you're tall.

[MParallel]

Lol you guys.

5’ and T-rex hands?

[hexdump]

6'2" and long arms + somewhat claustrophobic.

[gc325is]

lasted 15 min upside down in 90 deg temp... then you will just crush the clips, add some tape and it good as new except the contacts are still worn out.

Yes the red tip must be pulled out to remove and the white plunger pulled up as is height adjustable. It will auto set a height when replaced and the brakes are pressed to get a proper light on gap. BUT IF you press the white plunger in too far in while installing, the lights will be on all the time as they need to be pushed in by the pedal.

Contacts springs are weak and need cleaning to work and mine were misaligned and only 1/3 of the contact is used.

[BrokenBimmer22]

Dear Rakshas,

I had this warning coming up often last year. Weirdly enough, it has stopped. Even when it was on, my brake pedal always worked as intended with the lights.

Thanks,
BrokenBimmer22

[E36 Em Tree]

Lol you guys.

5’ and T-rex hands?

Basically haha

[gc325is]

the 4 pin switch means one set could fail and the other be OK. I think the other set is for cruise control operation.

[MParallel]

the 4 pin switch means one set could fail and the other be OK. I think the other set is for cruise control operation.

Totally unrelated. I explained in a previous post what is for what.

Just for the record, the brake switch is used as an input signal for cruise control module, but has nothing to do with it being 2 or 4 pins.

[Edrich]

I replaced the switch but now find that the fix will last for 20 - 30 minutes and then revert to full time brake lights. I pull the white plunger back out to full extension, and there's some clicking sounds, and then bring the pedal back to push it back in. Am I doing something wrong with setting the plunger? Ed

[blckstrm]

Is it popping out of place? Is the bracket misaligned or something?

It's possible you might have a faulty switch. Hopefully you got it someplace like FCP where you can replace it...