Brake light switch replacement/adjustment/repair?

Falcon4 · Post by **Falcon4** » Fri Oct 26, 2007 6:34 am

Pretty sure you're all sick of seeing topics by me by now... but you know, sad as it may seem, I hold this forum pretty high for the number of auto tech geniuses we have here. You guys seem to be mostly above "how i aer fix my start problem", more into "how can i get more gigas from my 2.haet?". So that's sweet. Plus, once this is posted, it'll be the only topic on the Internet addressing the Fiero brake light switch. Or stuck brake lights on a Fiero at all. Google showed up zero relevant results for "fiero stuck brake lights" and only product results for "fiero brake light switch". So hey, thank me later.

Aaaanywho, here's the problem. For a little over a month now, I'd sometimes walk around the back of my car (usually on a, uh, delivery), and see that my tail/parking lights are seemingly on, except for one slot/bulb. Strange... but usually, by the time I got back, they were off again. The first time this happened, it was after I came home from a bad day at work, had stuff piled high on top of the car, and when I saw the tail lights stuck on, let me tell you how pissed I was... especially after setting the stuff back down on top of the car, fiddling around half-sitting in the driver seat, and having a downpour of laptop and pasta on my head. Mhm.

Forgot about it for a while, I just let it do its thing, figured it was a wiring fluke or a weird bulb problem. It stopped after a few minutes so I knew it wouldn't kill my battery. But today, it happened again, and I thought "hmm, that's pretty bright for a tail light...", so I went inside and stepped on the brake. No change in the lights when I stepped on the brake! I let off the brake and the lights turned off. Oh, lookie, we found the problem!

This prompted two interesting thoughts. First, what the fuck has the back of my car been looking like on the road?! Like one of those dumbshit left-brakers, leaning on the brakes? Second, where the hell is the brake light switch at? And is it a maintenance item, something that needs to be replaced after 20 years? I feel like such a doof driving like this, with my brakes seemingly being held down as I drive... ahhh. Such a bad image...

And as usual... thanks! :thumbleft:

edit: The Chilton's manual is, as usual, one hundred and ten percent useless on the subject. No reference whatsoever (except in the body wiring diagrams) to the brake light switch...

Falcon4 · Post by **Falcon4** » Fri Oct 26, 2007 5:40 pm

Nevermind! As anyone that's probably ever looked under the dash would know, there's a hugely obviously visible switch sitting right there. Mine was knocked back a few notches, making it touchy at best as to whether or not it'll actually engage (?) and turn off the lights. And best of all (er, depending on if you're proactive or retroactive...), it was easy to fix since it just slides/clicks on one-way teeth like a wire tie. So I just pushed it up a little and voila, now I have a little more error-room in the brake pedal.

Well, now there's a Google result for this topic as well. Yay, go RFT! :thumbleft:

befarrer · Post by **befarrer** » Fri Oct 26, 2007 9:19 pm

MY Chevette that I drove a few years back had play in the brake pedal from a worn bushing or something, and if you hit the back of the pedal with your foot, would adjust the brake light switch to the point that it would sometimes stay on, I would just keep reaching down there and pushing it in. I could do that while driving, but maybe check for that play, may explain why it was out to begin with.

Falcon4 · Post by **Falcon4** » Sat Oct 27, 2007 4:35 am

Well, as it would turn out, I got home today from a drunk spree of happiness I"m still working off (see?), and saw my brake lights still on. Mhm. I pulled the pedal up with my foot, no help. Wha? I pushed and released the pedal, and it turned off like a toggle switch. Oh that's just great. Looks like I'm in for a new switch.

p8ntman442 · Post by **p8ntman442** » Sat Oct 27, 2007 9:02 am

depending on year, you may have two brake light switches. Both in the same under dash location, one for the middle brake light, and one for the sides. When the pedal is depressed, the switch is closed under spring pressure, and when the pedal returns, it pushes on the plunger, against the switches internal spring and it opens the circuit, turning the lights off.

your switch is not far enough down for the pedal to push the plunger back when it returns. You need to adjust the switch again, towards the pedal. It may be slipping back and you might have to get some pliars under there to tighten the ring that holds it onto the pedal assy.

P.S. dont google it, use the search function for this forum.

phpBB/viewtopic.php?t=3810&highlight=switch

Falcon4 · Post by **Falcon4** » Wed Oct 31, 2007 3:49 am

Guh...

Well, tonight it did the same thing. So while the lights were stuck on, I went under the dash once again, and checked things out. Both (yeah, looks like there are two, one huge switch and one smaller one I adjusted) were solidly pressed fully "in". So, I checked the lights (still on), pressed the pedal, the lights stayed on, then pressed the switches. They turned off. Released the pedal, they turned off again. Definitely something weird wrong with the switches. But what? =\

I'm guessing I should just disconnect them (one at a time) and disassemble, inspect, etc., them... because that's one embarrassing problem.

p8ntman442 · Post by **p8ntman442** » Wed Oct 31, 2007 9:09 pm

go to a mjunkyard or parts store and get two new switches, they will be cheap, you will save time upside down under the dash, and the problem will go away permenantly. Taking apart the switches and reinstalling them will most likely give you intermittent problems.

Falcon4 · Post by **Falcon4** » Wed Oct 31, 2007 11:19 pm

Well, online shopping with Autozone, I found a new "stoplight switch" that looks right, for pocket change ($6). Can't find the other, much bigger, switch though. Guessing it works fine since my cruise doesn't have a problem with "canceling" with the brake, although I don't know if that's on the same brake switch or not. Strange that there are two brake switches...

Also going to add some stuff for an oil change... might as well do it all in one trip

Falcon4 · Post by **Falcon4** » Sat Nov 03, 2007 9:43 am

Oh, well, a little update on the switch problem...

I went off and bought the switch, of course. It was super-cheap, like 6 bucks, like I said. And, also, like I said, bought some oil change stuff, including a little 2-ton rolling hydraulic jack thingy for propping up the back to change the oil. Yay. Grand total, set me back about 30 bucks, the cost of, well... a usual oil change when not doing-it-myself.

First thing I did was take apart the new switch. Yeah, only I. I stared in awe at its inner workings. Two contacts on either side of the button-shaft, normally contacting a center pole that goes through a slit in the center shaft. When the switch is pressed, the contacts are separated from the center conductor. When the switch is released, the contacts press the center conductor. Simple enough. The cruise (I'm assuming) is a normally-off part of the switch on the end of the shaft that simply connects two contacts when the switch is pressed in.

Then, I pulled out the old switch and put the new one in. I pulled apart the old switch and the problem didn't occur to me until a while after I put it all away - there was a tiny grain of metal that had accumulated over the years of arcing, that seemed to intermittently stand up on end, bridging the gap between the two contacts. There was also very noticeable black char all over the place, again, from all the years of arcing four (or more) light bulbs every time a foot contacted the brake pedal. That little piece of metal sometimes bridging the contacts caused, you guessed it, the lights to stay on when the pedal was up.

So all in all, it could have easily been fixed, but fuck it, I'm slowly replacing all the parts I can find anyway - plus it only set me back pocket change. Oh, and the oil change? Well, I figured out why so many oil places had a "problem" with my car... there's a weird oil drain plug that "pinches" the plug hole instead of screwing into it! You know, like those plant hangers with "wings" that spread out, and you shove it into the hole, and that's it? That's kinda like what I found. You don't take the drain plug all the way out, you just loosen it, loosen the rubber seal, and let the oil drain out. Weird little find. The oil filter (which everyone always has problems with) went on effortlessly without a drip. And to think, I was left stranded one day without oil immediately after an oil change because some dipshit couldn't figure out how to get the oil filter on. Sigh...

p8ntman442 · Post by **p8ntman442** » Sat Nov 03, 2007 10:17 am

in all my years, I have found that replacing switching contacts is a sure way to do the job twice. You think you have it all set, get it in go for a drive and the problem comes back. I'm sure you will enjoy years of problem free tail lights with your new switch. $6 well spent.