Can 12V Power Wire Provide Power To Overhead Upright With Lights On Trailer

Updated 04/23/2026 | Published 04/19/2026

Question:

I want to convert the wishbone PWC trailer I'm converting into a kayak trailer to 7-pin with a junction box. My reason for doing so is in part because I would eventually like to add an overhead upright with work lights. Am I correct in assuming the black 12v power wire could be used for such a purpose? Does the 12v power wire stop providing power when my truck is turned off? I also would not need the blue trailer brake wire, as I don't have trailer brakes on this small trailer. Thanks for any help!

asked by: Matt

Expert Reply:

Hi Matt! Yes, you can use the black 12V power wire in the # e99011 to power those lights. I can't say for sure if your 12V pin has power when your truck is off or not. Some do and some do not, you will have to test for power to be sure. You can leave the blue brake output wire attached in the box with nothing running to it, it won't hurt anything.

Where do you typically take your kayaks?

expert reply by: Robin H

etrailer Trailer Wiring 7-Way Upgrade Kit
(click to enlarge)

Matt

4/23/2026

Thanks! The upright will probably go on later, so I may just leave the black wire empty for the meantime then, too. I fish rivers mostly, some lakes.

Robin H.

4/23/2026

@Matt you're welcome! If you find that you don't have constant 12V power you could always run an additional line to the 7-way, or add a small battery just for the lights on the trailer side. If you need anything else don't hesitate to reach out.