Unusual brake light problem. Please help

[Severedokie]

Good morning! To get right down to it, my brake lights are not working. All my other lights are working as designed. Turns, instrument, tails, all of them. I chased it down to my brake switch, which as we all know is the common problem. However, I changed my switch out for a brand new delco switch and nothing. More over I can plug my old switch in(the new delco switch will do the same) and manually trigger the switch in my hand with a screwdriver and all my lights operate as they should. It’s like the switch just moves with the entire pedal assembly without trigger in the switch. I have no idea how to even fix it without potentially yanking out the whole assembly and replacing it with a unit from the salvage yard. Please help, I’m tired of people telling me my lights don’t work.

 

[Dirty Bird]

Good morning! To get right down to it, my brake lights are not working. All my other lights are working as designed. Turns, instrument, tails, all of them. I chased it down to my brake switch, which as we all know is the common problem. However, I changed my switch out for a brand new delco switch and nothing. More over I can plug my old switch in(the new delco switch will do the same) and manually trigger the switch in my hand with a screwdriver and all my lights operate as they should. It’s like the switch just moves with the entire pedal assembly without trigger in the switch. I have no idea how to even fix it without potentially yanking out the whole assembly and replacing it with a unit from the salvage yard. Please help, I’m tired of people telling me my lights don’t work.

 

[Dirty Bird]

Check the brake light switch trigger Pin (or stud) at the top of the brake pedal just below the pivot pin if it is bent or loose it will cause the whole assembly to move forward and backward and not trigger the brake lamp.

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[Severedokie]

I’ve looked at it very closely and it doesn’t look bent, broken, or bad. I found it odd a bushing was used in the design from GM but they haven’t been known for great engineering over the years.

 

[someotherguy]

Year model please.. always.. the 88-93 vs. 94-up brake switch is totally different design

Richard

 

[Severedokie]

Year model please.. always.. the 88-93 vs. 94-up brake switch is totally different design

Richard

Sorry about that, 97 Sierra.

AND further update for anyone searching later down the line. I’ve followed everything down to the letter in the factory service manual. I have all factory delco parts and all the electronics in question have passed continuity test. I’m going to changed the actual pedal this weekend if I can’t figure anything else out.

 

[KRS1]

Yes, it might be the pedal setup as you have tested that a signal goes to the lights..

 

[bugdewde]

Not sure if it applies ..... but the brake light circuit goes through the hazard switch in the steering column.
Unsure if it's upstream or downstream.

A test for it is if the 3rd brake light works..... but not the rears. (At least on a Suburban).
I know I had to replace it on my '99 Suburban. I even was able to "shim" the switch on the column with some pennies wedged in the column cover hole and the switch button. Worked for quite a while like that.

 

[Severedokie]

Not sure if it applies ..... but the brake light circuit goes through the hazard switch in the steering column.
Unsure if it's upstream or downstream.

A test for it is if the 3rd brake light works..... but not the rears. (At least on a Suburban).
I know I had to replace it on my '99 Suburban. I even was able to "shim" the switch on the column with some pennies wedged in the column cover hole and the switch button. Worked for quite a while like that.

Now that's someting. My hazard light switch acts weird as hell. I can sometimes get my hazard switch to turn my ignition on. I didnt even suspect the two related.

 

[AK49BWL]

That's a pretty clear indicator of being the problem lol. The hazard switch is between the brake switch and the lights.