Troubleshooting Trailer Battery Backfeeding Into Truck Lights

Updated 06/12/2020 | Published 06/11/2020

Question:

We put a new trailer connector on our camper, somethings wrong with the wiring, when we hook up the running lights and shut everything down, while running lights are disconnected and hooked to the truck, trucks running lights come on and it is draining the battery on the camper

asked by: Bill

Expert Reply:

From what I can tell of your explanation, it sounds like the trailer battery is backfeeding into the truck, causing this issue. The only way I can think of that this would happen is that your 7-way like the 7-Way Molded Trailer Wire Connector # H20043 is not pinned correctly. I'm not sure which trailer connector you purchased from us so the best I can offer is for you to ensure the 7-way is wired correctly by function instead of by matching colors.

I have added links to some help articles for you to check out as well.

expert reply by: Kyle S