Troubleshooting Trailer Loading Lights Connected to 2015 Dodge Ram

Question:

I have a 2015 Dodge Ram 1500 Laramie when I hook up to my bumper pull horse trailer with the 7 Pin the Exterior flood lights and the Interior lights do not work when hooked up to the truck. I did not have this problem with my 2016 Chevy 1500 it gave power to all of the flood and interior lights and never had a problem. Am I missing a fuse or a relay in the Ram?

asked by: Jeremy R

Expert Reply:

From your description it appears you do not have continuity from the batteries 12v supply to the pin for lighting. This may be due to a fuse or absence of that pin connected on your Ram where it is/was on the Chevy. Please see the attached wiring diagrams for assistance in trouble shooting and start with ensuring the pin for lighting on trailer is hot on the vehicle side.

When referencing the 7-Way RV Plug diagram that I have attached, make sure you are looking at the plug the way the diagram is showing you. Keep in mind that it isn’t always as straight forward as matching the colors, match the functions, not the colors. Ensure your ground wire, which is typically white, is securely attached to the frame on both the truck and trailer side. You will need to then check for power and continuity. I simple voltage continuity and current tester will suffice, such as # # PTW2991. From your description, I am thinking you do not have power being supplied either due to the pin not connected to the battery or, you have a bad fuse for the circuit. Check fuse F79 (Clearance Lights) first. I don't know what way your interior lights are wired, which circuit, but the same circuit that clearance lights are on is a good starting point. If that fuse is good then check the remaining fuses for the tow circuits. F28-F30, F53, F81. This is located under the hood drivers side front.

expert reply by: Michael R