Diode for Dual Purpose Reverse and Aux Flood Light on Trailer to Prevent Backfeeding

Updated 02/24/2022 | Published 02/23/2022

Question:

I want to mount a light bar on the back of a 20foot enclosed trailer. I would like to use the light bar as reverse lights actuate when truck is put into reverse and an auxiliary light so I can mount a rocker switch in the back of the enclosed trailer to turn the lights on when the truck is in park. If the light bar was directly wired to the reverse light pin on the 7 pin trailer wires I would think everything would be fine, but if I also supply the 12V power wire on the 7 pin at 11 oclock to the lightbar with a rocker switch I am not sure if I would get backfeed and mess anything up in the truck. RM-790 looks like it would work, but I am not sure if this is the correct part for the job. I attached a schematic of what I think may be correct. Thanks!

asked by: Colten N

Expert Reply:

You could use the diode part # RM-790 as a way to prevent backfeeding to your vehicle reverse light circuit when using the switch from the 12 volt power circuit to power the light.

expert reply by: Jameson C