Break lights?

[ownedueasy]

Ok driving to work one day I got pulled over for no break lights which was news to me. Ever since then I parked it and haven't drove the truck. Finally getting around to fixing it and it has me 100% puzzled. All fuses are good, as so is the flasher and turn signal relays. Break switch is also good. I've tried them out of 3 different trucks known to be good.

 

https://youtu.be/uzAWqGT9Goc

That's a video of what the truck is doing.

[gogmorgo]

You got trailer wiring? How janky is it?

Do you have power at the taillight harness connector? How's the ground behind the driver's side taillight?

[87MJTIM]

My experience from years ago was also no brake lights.  Tail lights, turn signal and flashers all worked. I replaced the brake light switch, but still nothing.  I studied a wiring diagram and noticed that the only location for brake lights ran through that the other light systems did not was the multi-function switch in the column.  (Mine has cruise control.)  I replaced the multi-function switch and now my brake lights work.

 

If you don't have cruise, then this may not help.

[Minuit]

Hazards work?

[ownedueasy]

No, hazards do not work they stay lit up and don't blink when engaged. I could possibly be mustaken, I will check again when I get home.

[mikekaz1]

what about the ground behind the drivers tail light?

[ownedueasy]

The ground is good, I cleaned it to bare metal. The connector under the truck was cleaned out also.

[mikekaz1]

I think your hazard relay might be bad, interrupting the brake circuit.   try swapping relays between flasher circuits.

[ScottJeep]

Maybe reaching here.... Have you done the dual diaphragm brake booster?  

 

My own brake lights do not come on often unless I STAND on the brakes. 

 

Need to tweak my brake light switch / booster shaft connection. Had to add some material (via aluminum tape) when I did mine. 

[ownedueasy]

Tried swapping relays around and nothing, Scott mine don't come on what so ever. Drivers side rear when turn signal is on 2 bulbs blink, passenger side rear turn signal on only 1 bulb blinks?

[Eagle]

Always begin with simple things. When you say the hazards light up but don't flash -- do the actual rear lights light up, or are you just looking at the indicator on the dashboard? Remember, the taillight bulbs have two filaments, a lower power one for tails and a brighter one for brakes, turns, and hazards. I have seen Jeeps in which all the brake light filaments were burned out but the taillights worked. It's not common, but it is possible.

[G O B]

Bulbs and sockets.  Check for the proper feed directly at the contact in the sockets. Check for ground at the socket shell. Use new bulbs. If this is not the problem, work forward from there.