i am trying to find out how to wire new tail lights for the flatbed i just put on my2004 dodge ram 3500. I have all the blinkers, hazards,and brake lights working but when I turn on my headlights my brake lights will not work?

 

On some of the older Dodge systems, the brakelites and turn signal use the same filament. On a two filament bulb, the other filament is for the tail-lamps.

If your using a new wiring harness kit,maybe the manufacturer can head you in the right direction.