Trailer Wiring Conversion from 4-Way to 7-Way

Question:

I have a gooseneck stock trailer and I’m in the process of re wiring the whole trailer. The old wiring plug to the trailer was a four plug and I’m putting in a 7. My question is on the new 7 plug harness should I run my running lights to the accessory red center plug, or should I tie into the taillights brown? Thanks for any advice you might have, this is my first trailer ever attempting to re wire.

asked by: Loren

Expert Reply:

When wiring your gooseneck trailer from the previous 4-way to the 7-way, I recommend connecting the brown running light wire to the taillight/running light pin and not the center pin. That center pin is utilized for reverse lights.

You may want to consider using a junction box like the Trailer Wiring Junction Box # 38656 to make the wiring easy to connect and troubleshoot should the need arise. If you haven't already purchased the 7-way, my recommendation is the 7-Way Molded Trailer Plug with Junction Box # HS381-9000 for a molded 7-way and a simple installation.

If you will be adding 12V power for a trailer battery or electric trailer brakes I recommend 10 gauge wire # 10-1-1 sold by the foot. I've attached a trailer wiring article as well as one on trailer lighting requirements to assist.

expert reply by: Jason S