Brakelights don’t work – why?

by ryandriftingfat on June 13, 2010

Had to hunt down problem number one with the new car today, my friend drove behind me and said the taillights weren’t working.

My bulbs were fine otherwise so I didn’t suspect it was a bulb.  My wiring harness is untouched from what I’ve seen so far, so I ruled out wiring quickly too.  I went for the fuse box.  Checked the fuse that said “Stop Lamp” and surprise, no fuse.  Plug in a 15A fuse and boom, taillights work.

Well, not so fast.  I noticed that brake lights were on even though I was sitting still.  No good.  At least I know now why the previous owner removed that fuse, the brake lights never go off.

I spent some time going over diagrams to find places where there could be a fault and the only other place that made sense was the switch.  Googled for the switch and I found this thread:

It seems that there is a plug that attaches to the brake pedal that pushes down on two switches.  That plug deteriorates over time, as you can see in this pic (on the left):

Those pieces fell on me when I was working under the dash.  In the pic below, you can clearly see where the plug goes, and the switch having no way to engage, thus the constant brake lights ON condition.  One thing to note, there are two switches there; in the pic, the lower one is NOT the switch that activates the brake lights.  I didn’t notice the second one at first, but there are two switches and two holes there.

(orientation on this pic is tough I know, it’s roughly at the top of the brake pedal looking towards the speaker in the driver door)

I happened to be taking parts of the interior out of the trunk the same day that I did this and realized that I already had some plugs that would fit perfectly.  An example of the plug is in the first picture, on the right.

If you insert the plug with the rounded side toward the switch’s engagement rod, the switch will engage and it’s about as close to stock as can be.  Good luck with this, it’s a PITA to do with everything installed.  I had to use a lot of force to engage the brake (to get space between the switch and pedal), engage the switch (for even more room) and insert that plug.  It’s in a tight, awkward position and it’s tough to get in there but I was able to do it myself.

I’m not sure that these plugs are the BEST way of doing it, but I know I’ll be working with the column dropped at some point in the near future, so I can do a good job then.  Until then, plastic it is.

EDIT (6/8/12): This plug has been in place for almost 2 years and it still looks perfect. I had my dash and steering column out during my build process, so I was able to look at the switch mechanism in greater detail. That plug I used had no signs of wear and was still working perfectly. No sense in fixing what isn’t broken – I left it in. At this point I’d say those plugs work just as well as any other replacement plug.