Flaky brake lights.

[Mean_Green]

Had it in for tires and an alignment today. When they pulled it into the bay and on the alignment rack, I noticed the brake lights didn't come on. Tailights, center high mount and the auxiliary LED strip I added, none of them lit. I called the tech's attention to it and he tried a couple of things including setting a pressure bar to hold the pedal down, to no avail. While it was on the rack (pressure bar still in place), and he was out in front of the vahicle looking at the alignment machine, they all came on. I drove it therest of the day and when I got back home, I tried it in front of the garage door. None of them lit again.

When they're on, they're steady, no flickering.

Can't be a fuse if they come on at all.

I don't think it's the strip I added since the factory lights and the high mount act the same way.

The only common point I can think of is the pedal switch. But I can't see it to find out how to test it or adjust it, if possible. Or to see how to remove and replace it.

 

[Mean_Green]

You don't really have to remove the pedal, do you?

 

[Mean_Green]

How should this work? Is it just a dry contact wire to wire? Or contact to ground? Is it passing 12V? Or just a signal to the BCU?

 

[OR VietVet]

Watch a you tube video. No pedal removal needed. There is a harness connector plug in. Crawl under there and look.

You added some lights? LED lights?

Please create a signature with vehicle info. Otherwise, it is guesswork when you ask for help.

 

[Mean_Green]

No 'Tube stuff here.

Pictures and diagrams found from searches are inconsistent, showing multiple different vehicles. None of them discuss operation and testing.

 

[OR VietVet]

No 'Tube stuff here.

Pictures and diagrams found from searches are inconsistent, showing multiple different vehicles. None of them discuss operation and testing.

That's because so many vehicles, different makes and models, will be the same work involved. Tahoe, Yukon, Suburban, Silverado and Sierras cross over in so many places.

 

[Eman85]

It's a real pleasure to change that switch, no pedal removal.

 

[Mean_Green]

^^^ I'm seeing that. Up and over and behind heavy brackets and braces. I could just barely get my hand to it. No idea how I'd get one out and back in.

BUT ....

I must have wiggled it enough because I now have brake lights again. Also added a small LED tapped off the trailer harness and mounted inside along the right barn door frame so I can see it in the rear view mirror. At least I can keep an eye on the problem that way.