How to Wire Up Trailer So that Reverse Lights Can Be Used as Auxiliary Lights on Switch

Published 11/20/2018

Products Featured in This Question

Starter Solenoid - SPST - 12 Volt - 100 Amp - Continuous Duty - Grounded

(13)

$34.79

12 Gauge Wire - Black Primary - Per Foot

(30)

$2.01

Derale Lighted On/Off Switch for Electric Fans

(4)

$6.75

Question:

Hello, i have an enclosed trailer with 7 way plug, it has 2 LED pods as reverse lights wired to the reverse line of the 7 way plug. What id like to do is use these LED reverse lights as auxiliary lights also, regardless when i am or when im not connected to a vehicle. I have a deep cycle aux battery on the trailer already. Basically i want to keep the connection to the reverse lights of my truck but when my truck isnt running i want to use the auxiliary battery to run the reverse lights by a light switch that i dont need unplug tow vehicle also dont use tow vehicle battery and can by the flip of a switch in trailer, those reverse lights turn on using aux battery. How do i do this? Use a SPST, SPDT, DPDT switch inside the trailer adding anything else to prevent the 2 batteries from connecting each other?

asked by: Greg M

Expert Reply:

What you would need is a switch like the # D16740, an isolation solenoid part # PK5231201 and some wire like # 12-1-1 (sold by the foot).

You'd run wire from the positive post of the battery to the terminal on the side of the solenoid and then on the other side run wire to the lights you want to activate. Next you'll run another wire from the battery's positive post to the switch and then from there to the center pin of the solenoid. This will activate the solenoid with the switch and allow the battery to be active when the switch is on.

expert reply by: Jameson C