Question:
green/brown and yellow green , then solid yellow what goes to left and then what goes to right side, is red wire needed ?
asked by: Alan D
Expert Reply:
The typical 4 Flat will use a white wire for the ground, a brown wire for the running lights, a yellow wire for left turn/brakes, and then a green wire for right turn/brakes (quick diagram included). Usually in that order as well. With that said, it does not sound like the wiring on your trailer follows this pattern, so the only way to know what does what is to either follow the wires to see where they go, or the much easier route of testing the 4 flat ports for their functions. This will require a tester, like the # PTW2993, but it will be much quicker and easier than tracing the wires.
I included an article all about getting a 4 Flat all wired up for you to check out as well. It will help.