Brake light switch orientation on the pedal

[LTDScott]

I recently swapped the brake booster on my car to one from a '93 Cobra, and this weekend while driving I realized my brake lights didn't work. I reached under the dash and could move the switch, and when I pushed the switch all the way up, the brake lights would illuminate (in fact I could get the switch stuck in that position which means they stayed on), so the switch is good. I did research online but I'm not convinced I've got the switch installed correctly.

In order of installation on the "stud" that protrudes from the pedal, I have:

- A washer (it's actually a broken-off piece of a bracket - I think it was the original cruise control cancel switch
- The rod from the booster with the bushing installed
- The brake light switch straddling the booster rod, with electrical pins facing the driver, and the open (notched) part of the switch facing the passenger side of the car, and the full enclosed round hole facing the driver's side
- Plastic washer
- Clip

It looks like this, except the notch is facing down instead of up (this is from an early Cougar site where the switch is "upside down" compared to Fox cars):



In other words, the switch looks like this when viewed from center console:



As far as I can tell, this is correct, because the purpose of the notch is to be able to pull the switch up and off the stud on the pedal without having to slide the booster rod all the way off. Is this right? Also, what's the purpose of the divot just in front of the notch? Is it supposed to line up with something on the booster pedal to keep the switch from rotating too far?

If I have it right, any ideas why the metal face of the plunger on the switch isn't being pushed in far enough by the flat surface on the booster rod? When testing the switch by hand, it only takes a small movement of the plunger to turn the lights on. It seems like there may be too much clearance between the switch and rod? This same style switch is used on lots of older Fords and I've seen some forum posts saying to try bending the face of the plunger on the switch outwards a bit to reduce the clearance, so I'll give that a try first but I'm open to other ideas.

[LTDScott]

Well, I was able to solve the problem by bending the metal tab that pushes against the plunger on the switch outwards so the clearance between it and the booster rod got taken up. Still no idea why it stopped working, but glad it was a cheap fix.

[ZephyrEFI]

Wait.. what metal tab did you bend?

Look at all those bushings. I don't have any of that. Maybe that's why my brake light switch gets out of whack and catches on the steering column bracket so i get my pedal stuck down...

[LTDScott]

Forgive the crudity of my diagram. I bent the brass "tabs" on the top and bottom (which push in the switch plunger) outwards toward the direction of the arrow so they're closer to the booster rod. I also bent the two parts of the switch which goes over the brake pedal "stud" and straddles the booster rod inward so the switch has a more snug fit. I think the small divot in front of the notch is meant to prevent the switch from fully spinning on the brake pedal stud by butting up against the booster rod. It's kinda hard to explain.

The brake lights still don't illuminate quite early enough for me, but I don't think there's anything else I can do considering the activation of the switch relies on the relationship between the brake pedal stud and booster rod changing slightly due to some built in "slop."



If your car is missing the bushings/washers, no wonder you're having the pedal issues. That's a safety concern, and a kit with all of the bushings is cheap.

[ZephyrEFI]

Okay, i had a feeling that's what you meant.

Yeah, it wouldn't seem to be a good thing to have my brake pedal stuck down. I'll have to grab one of those kits.

[ZephyrEFI]

Got under the dash just now and the spacer is there, but the bushing isn't. And how about that, i had 3 of them in my drawer of stuff. Installed.

If you want your taillights to come on sooner, you could go LED...

[LTDScott]

I've considered it. The challenge is finding LED bulbs that disperse light across the light reflectors well. Most LED bulbs suck in that regard.