How to Power Utility Light In Trailer That Has 4-Way Connector

Updated 01/06/2016 | Published 01/04/2016

Question:

Hello, I have a 6 x 12 enclosed trailer that has only one utility light inside and only works when the vehicles lights are on. Id like to add a second light and a switch so that both utility lights will turn on when plugged into my truck. Enclosed trailer has a 4-flat plug and truck has a 7 pin with a constant 12v supply. Im looking for help on how to wire both utility lights and switch. I will be converting the 4-flat on the enclosed trailer to a 7 pin plug for convenience. Thank you for the help.

asked by: Juan R

Expert Reply:

You are on the right track. You will need to convert the 4-way to a 7-way so that you can tap into the 12 volt accessory circuit of the connector to power the utility light.

For a 7-way with a 4 foot long section of wire you would want the part # H20043. Currently your interior light is ran to the running lights circuit of the 4-way wiring. You would need to run the light to the black wire of the new 7-way as that is for the 12 volt circuit.

I attached a chart that shows how the 7-way will wire to the rest of the circuits as well.

expert reply by: Jameson C