2nd Gen Non-Engine/Transmission No brake lights, directionals, melted wires

[BSander]

1999 3500 Rear Wheel Drive. I was towing a trailer and lost the brake lights trailer brakes and directionals. I was able to use the brake controller for trailer brakes, and the brake lights came on then. I found the fuse for the brake lights and the fuse for the directionals blown. Smoke came from the trailer brake controller so I cut the wires to it. I found the brake light switch and the wiring to it melted.

I replaced the melted wiring harness to the brake light switch and the switch and got brake lights back. I still have no hazards or directionals and the fuse blew when I replaced it. Any ideals?

 

[HHhuntitall]

Start at your trailer plug. I'm gonna wager the trailer plug is wired into the truck wire loom, and you don't have a tow package where the trailer lights are run off a separate wire loom and relays..... ... not good... . Look for wires melted to each other, then come forward under the truck, over the axle, behind the fuel tank, and up to the connectors behind the front, driver tire... . If no problems, then go to the tail lights, and then to the main light switch under the dash... . If it's affecting the brake controller, I'd wager the brake controller feed wire has melted into a turn signal wire, or caused a ground to melt into the turn signal wire... .

 

[BSander]

I pulled the brake controller out. The trailer plug wires all check out. I replaced the melted brake light switch, and wires. The lights worked fine, but still no directionals. I replaced the flasher and the fuse for the hazards and got directionals back, but noticed the 3rd brake light was on. I checked the brake switch and the switch and the wires were hot. I pulled the fuse (40 amp) plugged it in, then all the brake lights were on. I noticed the fuse was supposed to be a 30 amp, so I replaced it with a 30 and it blew.
Not sure why the 40 amp fuse did not blow, but the correct 30 did. I obviously don't have a direct short, but the circuit has much to high a draw.

 

[HHhuntitall]

Ok, so the brake controller is working correctly? Did you try unplugging the brake controller to see if it stops blowing the fuse?

The third brake light will work even without a fuse in it, as it feeds from the pedal switch. Usually, if it's on and the brake pedal switch is not activated, you have either a short from the trailer brake feed backfeeding into the brake lights, or the controller is faulty or not wired correctly. If the fuse is removed or blown, and the light is still on, it may be the same story... .

Occasionally, I'll see the trailer accessory feed short from the plug across the terminals to another wire, in this case, it would be a turn signal wire or the trailer brake feed wire..... If it's wired to code, the trailer accessory feed will be red, the turn signals yellow or green, and the trailer brake wire should be blue.....

If unplugging the brake controller doesn't solve it, then try unplugging the wire loom behind the driver tire and see if that stops the draw and blowing of fuses... . if so, then the fault is from there to the rear of the truck.....