Troubleshooting Wiring On 2010 Dodge Ram 2500 Diesel

Question:

I have. 2010 dodge ram 2500 diesel we hook a cattle trailer up to it and the right brake light stays on at all times even when not running. We hooked the trailer up to another truck and it works fine and this track has been pulling this trailer since new.

asked by: Trevor

Expert Reply:

Since you said the trailer works fine when connected to another truck and only has the problem when you are connected to your 2010 Dodge Ram 2500 Diesel, I think you will find the problem lies with either the truck harness or in the truck wiring.

First check for corrosion on the vehicle harness. Then using a circuit tester like part # PTW2993, check each of the connectors on the harness to make sure they are getting current only when they are supposed to. Make sure your ground wire is securely fastened to a clean, bare metal surface. A loose ground wire can cause a variety of issues. If the functions are not working properly on the harness, then use the tester and check the wires from the harness forward on the truck. If all of the wires are showing current correctly, you may need to replace the 7-way connector on your truck.

I have included a drawing that shows the 7-way connector you referenced, part # 37185, and where the wires are to be routed.

expert reply by: Jeffrey L