This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.
There may come a time when someone on the road motions to you about your brake lights not coming on. The brake pedal switch (Figure 1) in both the E30 and E36 BMWs gets a lot of use, and has a tendency to fail once and a while. Replacement is really easy, and should take only about 30 minutes maximum.
The first step is to verify that your brake lamps are not working. If you're by yourself, then wait until night time and back up against a brick wall. You should see the reflection off of the wall when you step on the brakes - if you don't, then your switch is probably shot. It's important to note that at least on some years, the BMW warning system that tells you when a lamp is out will not tell you if the switch is broken - you will have to figure it out for yourself.
The first step is to gain access to the switch. Remove the panel directly above the driver's side foot well. This panel is secured by a few screws (Figure 2), and a few snaps as well (Figure 3). In addition, you may have an electrical speaker unit attached to the panel. Disconnect the harness (Figure 4) and pull the panel down (Figure 5).
The brake switch is shown in Figure 6. It's the rater large switch assembly that moves in conjunction with the brake pedal. Remove the harness from the brake switch (Figure 7) and yank it out of it's bracket. I found that I had to break the plastic housing of the switch in order to remove it (Figure 8). That's perfectly okay, since you will be replacing it with a new one very soon anyways.
To finish the job, simply install the new switch into place, and reconnect the wire harness. Test the brake lights to make sure that they are working properly, and then reinstall the knee panel.
Well, there you have it - it's really not too difficult at all. If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs. If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one. Your continued support directly affects the expansion and existence of this site and technical articles like this one. As always, if you have any questions or comments about this helpful article, please drop us a line.
At the end, you instruct the readers to rip the switch out of the bracket. I just went through this today, and that is not the solution, though the solution is not obvious. In Figure 1, you see the brake switch. You will notice that the switch 'button' is extended out further than it is once installed; it sort of ratchets in after installation, maybe as a self-adjusting measure. The way to remove the brake switch without breaking it is to first depress the brake pedal. Then use pliers to pull the switch button out; it should measure about 1/2" from the body of the switch. Finally, see the white collar in the picture (on my car it was red), pull that out, too; that will allow the plastic hooks that hold the switch in place to be depressed and to release the switch from its bracket. I was in pain and yelling foul words today as I figured this out. I hope the next person has an easier time!