Thread: I need a new brake light switch!!!

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Here' mine monted in my 51 F1

dmw56,
Thanks, the picture is helpful. I was baffled by the fact that in the resting position the switch is "on", conducts. When your brake pedal is depressed that allows the switch to be "on" no matter how far the pedal goes forward. At least I understand how yours works but I have a MC under the floor so I have to think about this a bit.

Don Shillady
Retired Scientist/teen rodder

IF you buy a switch from a late model GM car with cruise control, there are two circuits, one opens on brake application and one closes. The one that opens can be used to unlock your converter and the one that closes is the brake light sw. From GM, the switch is less than $10 and is all mechanical....no hydraulics.

I have heard that the switch (pun intended) from the hydraulic-actuated style to the mechanical style is because you can actuate your brake lights earlier....as soon as the pedal is touched, the lights go on...theoretically sooner than waiting for the pressure. Of course, this allows the nimrods who left-foot brake to keep their brake lights on for miles and miles. (It's OK to left foot brake at the starting line).

Are there brake pressure switches that engage at lower pressures?

You can buy a pressure switch that engages as low as 10psi. This doesnt make the light response time significantly faster.

Another photo of the universal mechanical switch mounted on floorboard. Hope this helps.

Pat

Thanks Pat,

That is an excellent picture. The switch you show is the mirror image of the one I got from Speedway and today I looked at at least three, maybe four, similar switches in the Car Quest catalog, yours, the mirror image and two other ways the bracket faces but they are not cheap so I need to make the one I have work rather then buy all of them till I get one that fits. Then I ordered a low pressure switch from Ron Francis, but I am going back and look to see if I can mount the mechanical one I have in the way you show. That is a great picture! My hydraulic switch is in the lime already but facing down so I would need to bleed the brakes again if I put in the Ron Francis low pressure switch. To answer the question above Ron Francis does sell a low pressure switch to work with silicone fluid or just come on sooner. It is possible to put both switches on line in parallel and maybe I will do that eventually. It is hard to put a price on the help I get from this Forum, thanks again!

Don Shillady
Retired Scientist/teen rodder

Don the pic Pat shows is how mine was placed & mounted...joe

Thanks Joe,

I rotated that switch around the hole every way but the obvious orientation directly across the pedal arm, partly because my 'glass floor is flush and does not have the rib Pat shows and partly because I just didn't see it! That picture really helps me but I may have to shim the mount so that the arm of the switch is straight across.

Don Shillady
Retired Scientist/teen rodder

Don...you're welcome sir. Glad the pic jogged your thinking a little bit. I've been there many times before trying to figure out how to do something and usually overlook the obvious. As a matter of fact, my 9 year old grandson helped me with a problem this summer!! LOL

Good Luck

Pat

Originally Posted by Dave Severson

I use the two wire switch that is pressure actuated and can be tee'd into the brake line anywhere.... Cleaner setup, and one less thing to mess with under the dash! I get mine at NAPA, super cheap deal, easy to install.

While doing my search prior to installing one of these switches I found this thread . The way my plumbing is laid out it will be easiest for me to put the switch right after my MC and before the residual valve . It will be on the front brake side of MC . Will this work OK ?

Originally Posted by luckyfasteddie

While doing my search prior to installing one of these switches I found this thread . The way my plumbing is laid out it will be easiest for me to put the switch right after my MC and before the residual valve . It will be on the front brake side of MC . Will this work OK ?

Yes - good as any place

Originally Posted by IC2

Yes - good as any place

Thanks for the info

I just replaced my second brake light pressure switch. I had one go out right after I got the car and one went out over the winter (about 5 years later). While not a difficult thing to replace, I don't want to drive without brake lights either.

I read that too much current through the brake light switch can cause premature failure. Since I run halogen tail lights, a third brake light and sometimes pull a trailer with halogen lights and a third brake light, I figure I'm pushing the limits.

I installed a relay under the dash and connected it to fuse panel and the brake wiring. Now when I push on the brake pedal, only a small current goes through the pressure switch and it then supplies a higher current to all the lights. It wasn't hard to figure out and it's clean too. I also have another little LED light that I have in my third brake light that faces the front of the car, so I can see the light working in the rear view mirror.

One might have an issue with this setup as I've added a relay that can go bad too... but it is an easy - in the car fix, as I carry spare relays with me. It may not eliminate the pressure switch from going bad, but it could make it last longer.

Thoughts??
Jerome

Kurt, I went through two of the in line pressure switches in my T in two years. Finally had enough and replaced it with one I have used for years and years with no problems. It has been used on a lot of different Chevrolet cars over the years and has threads for most of the body, making it very adjustable. We also replaced the pressure one on my Son's T because it also failed in a year, and went to the one pictured below.

Here is a picture of it and the writeup from Advance Auto. All you have to do is build a little tab with a hole drilled in it so you can slip this switch into it. As the pedal moves it lets the button come out and activate your lights. I had the same one on my 27 for 7 years with no failures.

Don


ACDelco Stop Lamp Switch
Part No. D885 Warranty
Except CRCONT; Except POWER BRAKES; 2 DR, 4 DR, CONVERTIBLE


$8.89


Sorry for the small picture, that is all I could download from their site.