93 dodge Cummins dually. Equiped with class V Hitch and trailer brake control.
Brake lights stay on regardless of whether the truck is running or not. In addition,the harzards have never but that never bothered me b/c I dont use them. When I first bought the truck, I realized that turning the harzards on somehow caused the brake lights and turn signals not to work. I have been driving the truck for almost a year now and it recently started giving me problems with the brake lights staying on.........To keep from draining my battery, I have been turning on my harzards which in turn shorts the tail lights out......Since the harzards dont flash, there is no power being consumed and I dont have to worry about draining my battery.......
I have tried replacing the brake light switch located by the brake pedal and I have also replaced the turn signal/harzard switch with no sucess......I still have to drive with the brake lights all the time......Like i said, I turn the hardard switch to the on position to short out my brake lights which would otherwise stay on.

 

you'll have to trace the wires and find the short. Chances are there is some insulation worn off somewhere and its messing with the system...thats really the only way to find this problem if you have already changed the 2 switches

 

Did you put any different trailer light wiring on the pickup?

 

If you lift up the brake pedal does the light still stays on ??? why not remove the brake light fuse until you find the problem

 

Any updates??

 

Closing due to one time posting. TS can reopen.