I've got an '02 GMC 2500HD 4x4 6.0L with 4L80E with about 46,000 miles. My wife was driving behind me the other day and noticed none of my 3 brake lights were working... No clue on how long they have been out.

So I pulled over and checked all the fuses. In the dash and in the Electrical Center. They all looked fine and since I didn't have a multimeter with me, I swapped the fuses for spares or swapped with another used fuse. Didn't change anything.

I did find that my hazzards were not working (noticed this awhile ago) and put a new fuse in there. It was burned so the new fuse fixed the problem.

So I decided I'd try to find or adjust the brake pedal switch. I can't find it. Doesn't seem to be in the normal spot that all my old Chevy's have had.

I also pulled the taillights and the lightbulbs looked good. No blown filaments.

So, what is my next step? Does anyone know where the brake light switch is? Is this a known problem?

Please help, I'm scared to drive the truck in traffic with no brake lights. I don't know what kind of hazzard I am putting myself in, insurance and legality wise.

 

i would say a multifunction switch, thats the switch with turn signal, wipers and hazards. brake wiring runs through that, sometimes when this happens your cruise doesnt work either, thats a tell tale sign. pretty common on these trucks. brake switch isnt adjustable.

 

this happend to my 02 too. i still had warranty so i just took it in. i think it was a like a signal light switch. or some kind of switch. sorry im not much help.

 

Well I poked around under the dash some more and found a box/switch attached to the brake pedal lever. I'm thinking that is the brake light switch...

I didn't know the brake light wires ran through the MFL (Multi Function Lever)... I'll try my cruise control and see if it works. If it does, then I think I'll swap out the brake light switch.

I'm out of factory warranty, but I have an extended GMPP warranty, however it is a $100 or $200 deductable. Not worth it for this simple switch... If it turns out to be that.

Thanks for the help.

 

lol, if it is the switch then it will be worth it, those swtches are expensive, like 250, around there.

 

i mean the multifunction switch, not brake switch g/l

 

Wow, the MFL went up in price then... They used to be pretty cheap.

I checked and my cruise control still works, and when I apply the brakes, the cruise control shuts off like it is supposed to.

I bought a new brake light switch from GM ($16.15) but have yet to install it. Hopefully this fixes the problem.

And the switch is some new fangled contraption. It is a small white box (maybe 1/2" thick, by 2" by 3") and it is attached to the brake pedal lever itself.