Trailer Connector Running Lamp Circuit Not Working on 2014 Ram 3500

Question:

My brake lights and turn signals work but no clearence lights on my trailers. Hook trailer up to a different truck and they work

asked by: Charles C

Expert Reply:

Good thinking plugging the trailer into a different truck, by doing that you've eliminated the trailer as being the problem.

What's most likely going on is that the trailer running lamp fuse is blown. You can find that fuse in the engine compartment fuse box in location F29. Before plugging a trailer back in after replacing the fuse, you'll need to find out what caused it to blow in the first place, or you'll keep blowing fuses.

Begin with the trailer connector on the truck, examine it for damage or for corrosion on the pins, and replace it if necessary with # HM40975. Then, move on to the trailers. Beginning at the trailer connector, trace the running lamp circuit rearward until it connects to the taillights. Look for loose connections, pinched wires or cracked or worn wire insulation that would allow the circuit to short out on the trailer frame. Pay special attention to spots where the wire passes through a trailer frame member, as that's a typical spot where the wire could become worn. Find and repair the loose or damaged wire and you'll be good to go.

I'll also link you to a trailer wiring troubleshooting guide.

expert reply by: Mike L