Determining Taillight/Trailer Wiring Circuit to Install New Connector

Updated 04/13/2020 | Published 04/11/2020

Question:

Hello. My name is Dave. I just bought a used flatbed and it has 5 wires that the previous owner cut. So there is no ends just bare wire. I believe the colors are red green brown yellow and white. I have to double check I have a 2014 Ram 3500 Cab and Chassis with basic lights you can by at any automotive store. My question is how do I know which wires from the truck after I remove the taillights go to which wires from the flatbed. Or is there a different way this has to be done. Any help would be appreciated. thank you so much.

asked by: Dave M

Expert Reply:

Because there is no industry standard for wiring colors you will need to test the wires behind the tail lights to determine their functions on your vehicle. To test the wires you will need a circuit tester, # PTW2993. Have someone sit in the vehicle and go through the lighting functions (each turn signal, running lights, and brake lights) while you test with the circuit tester. That will tell you which wires do what. I attached a video that shows how to do this.

expert reply by: Jameson C