Troubleshooting Brake Lights Interfering with Turn Signals on a 2005 Ram 2500 with a Trailer

Question:

I have a 2005 ram 2500 I installed a flatbed on it and its a 4 wire system on the lights that trailer lights are 3 wire and they work fine till I hit the brakes while my blinker is on then my blinkers quite and just brakes im stumped please help not a resistor issue not led

asked by: Landon P

Expert Reply:

There's a possibility that this may be a grounding issue, but we won't know for sure until we do some tests.

First, check the ground wire connection points on the vehicle and trailer. Look for any corrosion, rust, or paint preventing a clean connection. If you find any, either clean the area or move to a better spot.

If there isn't anything preventing a clean connection, trace the wires to look for any pinches or frays. If you find any, replace those wires.

If that doesn't fix the problem, then we need to check the other functions. Use a circuit tester like part # PTW2993 to determine what each function is in your harness. Check to make sure everything is functioning properly without the trailer hooked up. If they aren't, check those wires to see which one needs to be replaced. If they are working fine, it's time to move on to the trailer.

Check those wires to ensure there aren't any pinches or frays.

Also, check to make sure your converter is wired correctly since you are converting from a 3-wire to a 4-wire.

If none of that solves the problem, let me know and I will help you further.