Ok, I've tried everything I can think of. I checked all the switches, changed the sending unit on the pedal. And still no brake lights? I can hit the hazards and they work though? I've done all I can think of and I cant get lights. Any help would be awesome!

 

My buddy had this same problem a while back. We tried everything.. We ended up running a new power wire to the brake pedal switch.

 

Have you had the dash out recently?

 

How did you go about running the new wire? I had the cluster out but I think the problem was there before that.

 

You can run a hot wire to the yellow wire on the plug. I believe thats the hot one.

 

did you ever fix it?

 

tail lamp circuit board corroded up? its mounted to the frame behind the spare tire.

 

Do you not have any brake lights?? Do you have a just the third brake light and no tail brake lights???? The multi-function switch is usally the problem. Apply the brake and have someone watch the tail lights then start playing with the blinker switch. If they begin to work then you know that the multi-function (blinker switch) is bad. The third brake light is the only one that does not run through that switch. Thats why the third one will work and the other two wont. Just something to check.

 

Check for power and ground either back to the lights or the board under the bed. Crawl under there and you'll see the harnesses that go to the lights and the board that they plug into. One of our members, "strapedforcash" recently came by my place and had his left tail light only inop. I checked for power and ground at the board under the bed and found that I had no power (You'll need a schematic for this BTW, so you know which wire to check). anyway, I followed the wire from the back of the truck, all of the way to the front checking for voltage. Had voltage at the fuse box but not at the circuit board, middle of the bed, between cab and bed...long story short, I found that where the harness comes down from the fuse box, through the wheel well, then takes a turn under the cab, was giving us the problem. Right behind where the front cab mount is, there is a grey clip that attaches the harness to the frame, and the clip broke. The harness was then vibrating against the frame where the tab for the frame mount is. The wire was wide open and corroded. Peter said that he was having intermittent problems with the light until it just went out permanently.

Moral of the story...might be worth your time to take a quick peek at the harness on the driver's side of the truck, right behind the wheel well, where the cab mount is, and see if the grey harness clip is broken...all of the wires run through there, and you may have a busted ground or something. If that's OK, start at the back and check for power and ground there, then lift up the fuse box and check the wires there for power and ground and see what you have. If everything is copacetic under the hood, I'd start at the tail lights, then move on to the connector under the bed, then it's your choice if you want to go from front to rear or rear to front. I went from rear to front and the problem was in the front lol. Good luck, and keep us updated

 

Ya I finally figured out it was my brake sending unit on the pedal.