Does Wiring Up Trailer for Winch and Lights Require Relays

Updated 01/05/2026 | Published 09/22/2024

Products Featured in This Question

Bright Way Trailer Breakaway Kit with Switch and 0.5-Amp Charger

(75)

$32.19

10 Gauge Wire - Blue Primary - Per Foot

(108)

$1.65

Question:

Hi, I am wiring up a utility trailer from scratch and will have reverse/work lights on it as well as a winch with battery. I would like to have a 4 way switch that will control the reverse/work lights to be powered by 1. Truck reverse 2. 12v constant from truck 3. 12v battery on trailer This way I can maximize the use of the lights. Can I just use a switch or should I add relays in? What would that circuit look like with 3 potential power inputs? Thanks

asked by: Nick

Expert Reply:

You can use just a switch and not have to worry about adding relays. It would require you to use a heavier gauge wire for the battery like 10 gauge part # 10-1-1 which we sell by the foot.

expert reply by: Jameson C

Jameson C.

1/5/2026

Hey, how did your wiring setup for the trailer lights and winch turn out using the heavier 10-gauge wire? Sharing what worked could help others planning a similar multi-power setup.