Troubleshooting Wiring on ATV/Snowmobile Truck Deck on 2013 Dodge Ram

Updated 12/23/2014 | Published 12/22/2014

Question:

I have installed a Marlon truck deck into my truck box. It has a wire harness with three wires brown for running lights and to power a light under the deck light, white for ground and a green which I think is for the back brake light. My friend wired his into the back of his taillight I would like to add a trailer plug so I can take the deck in and out easily. So I bought a four prong trailer plug and hooked up the white ground wire and the brown running lights then I tried hooking up the green to the green but of course when I turn on the signal lights the back taillight flashes. So I hooked the brown, yellow and green on the trailer plug all together and it seems that the signal light stopped but the brake light seems to be bright like the brake light is on all time. The deck is made of aluminum and the lights are LED just in case that may help.

asked by: Erin

Expert Reply:

The first thing I would do is make sure you are grounding your ground wire to steel and not aluminum. The next thing you are going to want to do is determine the function of each of the 3 wires. You cannot go by color alone because there is no standard color code. One way to do this is to attach each wire, one at a time, to a separate car battery and see what function turns on. After you know the functions of the wires you can match them to the 4 Way Trailer Wiring Color Code at the provided link at right.

I have also included a FAQ article on Troubleshooting 4 and 5-Way Wiring Installations.

expert reply by: Chris O