Where Does the RED Wire of the Wiring Harness C59496 Go When Installing on a Vehicle

Question:

My husband and I installed at Modulite #119192 in our 2008 Dodge 3500 with a CM flatbed. He delivers campers and trailers across the country, and after replacing 2 fuse-boxes because they caught on fire, we purchased this hoping to avoid another costly expense and down time. Everything seemed great, all the blinkers, brakes etc worked on the flatbed as well as in the trailer hitch plug. Until we shut all the lights down and the running lights on the pickup and flatbed didnt go off. We are at a bit of a loss as of what to do. We grounded the red 3-way wire. and when we went to ground the trailer plug, we had 2 grounds. Neither of them live. We stopped, did some research, and determined either would work. Now my questions is, Are the running lights not shutting down because A we should have used the red 3-way wire instead of grounding it. B did we pick the wrong ground wire on the plug? or C have we missed something completely different and dont realize it? Whoever installed our flatbed on that pickup must have wired it up in a hurry for the back lights, it was a bit of a mess to sort out. Any insight on where we went wrong would be much apprieciated!!!! Thanks in advance!!!!

asked by: Katy M

Expert Reply:

When you install the Wiring # C59496 on a vehicle whether or not you ground the red stop wire depends on the lighting configuration of the vehicle this harness is installed onto.

If you have a separate wiring setup where your blinkers and stoplights are on different bulbs/circuits then the stop light wire gets run to the stoplight circuit of the vehicle. If your vehicle has combined taillight circuits where the brake lights and the blinkers are on the same circuit then you would need to ground the red wire.

Otherwise you will want to use the circuit tester included with the kit to test the functions of all of the circuits you used to install this harness. It is possible that you used the wrong running light circuit.

expert reply by: Jameson C