Trailer Lights Stop Working, Blow Fuses when Connected to a 2001 Dodge Ram 3500

Question:

My company rig has no working trailer lights everything works fine until we move the trailer and hit the brakes keeps blowing fuses

asked by: James N

Expert Reply:

It sounds like 1 of 2 possible problems. First, there could be a short somewhere that is drawing excessive power and causing the fuses to blow. The easiest place to start checking is going to be the truck and trailer side connectors. Make sure each is clean and free of corrosion inside where the wires attach and on the pins.

You can also check the wiring on the truck and trailer checking for any pinched, frayed, or damaged wires and fix as needed.

The second possible cause is that if the trailer has enough lights on it that can cause excessive power draw and lead to some lights not working and blown fuses. To check that you can disconnect some of the lights and if everything starts working an no fuses blow then the likely issue probable was too much power draw.

In your question you used the word rig. If the trailer is a semi trailer then those have different functions on the 7-Way than a traditional vehicle side 7-Way and could be the problem.

expert reply by: Michael H