Troubleshooting Lack of Trailer Running/Parking Light/Tail Lights When Connected to 2017 Ram 3500

Question:

Ram 2017 3500 The running lights dont work on the trailer where would the fuss on it

asked by: Paul H

Expert Reply:

First check the running light circuit on your 2017 Ram 3500 using a circuit tester like # PTW2993. This function is on the 11 o'clock pin of your 7-way as you can see in the attached photo. If you do not have power there, check your fuses as outlined in your owner's manual.

If you do have power at the running light pin, then you will want to check the ground connections on your trailer. You will have a ground connection at each taillight, so you will want to check that wire, or the mounting hardware of the taillight which often serves as the ground. That connection needs to be bare metal to metal and free of corrosion or debris. If that connection doesn't change things, check your wire leading to that function using your circuit tester probing through the wire insulation. If you have power, then the ground connection is the issue, and you will need to use a jump wire from another location on your trailer frame. If you don't have power, trace that wire from the coupler end probing every few feet to find the short and replace with # 16-1-1 wire as needed which is sold by the foot.

I've attached a wiring article with diagram to assist.

expert reply by: Jason S