Does Trailer Wiring Really Need 10 and 12 Gauge Wire for All Circuits

Published 03/30/2023

Products Featured in This Question

Hopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard

(925)

$46.90

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

12 Gauge Wire - Black Primary - Per Foot

(30)

$2.01

Question:

We have a 40foot tandem axle industrial flatbed tilt trailer that has had so many wiring problems that we are going to bite the bullet and rewire the entire thing. I have learned a lot reading your QandA..... thank you. My problem is that the wires, which Im led to believe are original, from the brakes are like 24 gauge, these tiny little wires. Everything I have read in here says to use from 10-12 gauge. Im going to remove the hubs and rewire the wheels but now if I use 10-12 gauge, am I going to create a bigger problem? Also, the beating this trailer takes from the road conditions has caused most of the damage. Im trying to design a waterproofinch system as much as possible to try and prevent it. I did the taillights a month ago and didnt protect them as well as I should have and it is already destroyed. Limiting my splices to the main cable is goal #1 as that is where all of the problems really start. Im going to use conduit and junction boxes, as well as waterproof plugs at each light. Problem is finding waterproof connectors for larger gauge wire. I can see the larger size for brakes and the aux battery, but do I really have to use 12 gauge for running lights? Thanks in advance for any help!!

asked by: Tony G

Expert Reply:

You really only need the heavier gauge wires for the brake output circuit, the 12 volt accessory circuit (if being used) and the ground circuit. If you can I would run 10 gauge like part # 10-1-1 for each of these circuits. The other circuits can get by with much lighter gauge wire like 16 or so. Especially if the lights are LED.

We also sell 12 gauge wire by the foot with part # 12-1-1.

expert reply by: Jameson C