How to Power Trailer Lights from Reverse Circuit and Trailer Battery Separately

Updated 11/16/2020 | Published 11/13/2020

Products Featured in This Question

Roadmaster Hy-Power Diode - (Qty 1)

(329)

$16.72

Derale Lighted On/Off Switch for Electric Fans

(4)

$6.75

Question:

I have an enclosed trailer and some backup lights that I want to install on that back of the trailer. I would like to be able to have the lights activate when the tow vehicle is in reverse via the 7-pin yellow backup wire - and also, used independant of the tow vehicle, powered off a 12V deep cell battery. What switch or product would I install that would allow me to use the lights in both these scenarios, and how would I wire it?

asked by: Jay W

Expert Reply:

You'd want a diode like the part # RM-790. On the in side you'd run power from your trailer battery on one pin and then from the reverse light circuit on the other. On the circuit from the battery to the diode you'd need to install a switch to allow it to only draw power from the battery when you wanted it to. For that you'd need the part # D16740.

expert reply by: Jameson C