Adding 4-Pole Connector to Existing Trailer Wiring

Question:

I want to directly hook up a 4 pin into the junction box where my 7 pin splits into camper. I have a green red and brown wires and I can see a cut off yellow wire way down in the pigtail thats not hooked to anything so would I just hook up the white green and brown of the 4 pin wire ? Assuming that white is red or is yellow red? Adding a 4 pin for triple towing.

asked by: CORY P

Expert Reply:

A wire's color is not a reliable way to know the function it carries so to hook up an additional 4-pole to your existing towing setup you'll just want a circuit tester to allow you to confirm what each wire does. I recommend kit # 18252 which includes both a probe tester and a 6-foot vehicle-side 4-pole that will connect to the mating trailer-side 4-pole connector. You'll apply the tester to the various wires while a lighting function is activated and after you go through the functions you'll know which wire does what.

You'll also need quick-splice connectors # SWC501746-1 to make the connections once you've identified each wire's function. The 4-pole wire colors are white for ground, brown for running/tail lights, yellow for left stop/turn and green for right stop/turn.

If you need longer 4-pole wiring we do offer it in bulk as part # 16-4B-1 (sold by the foot) and you can use butt connectors # 05731-5 to connect it to part # 18252. If you wish you can refer to the linked article on wiring.