What Gauge Wire Should be Used to Wire Trailer Brakes
Updated 05/26/2025 | Published 06/23/2014 >
Question:
Hi, etrailer recommends to using Deka 10-2 gauge wire for running electric brakes to a tandem axle trailer. If this is the case, why does 7-way harnesses with molded plugs only have 12 gauge wiring for the brakes? Tghanks,
asked by: Ray S
Expert Reply:
That's a very good question, we tend to be extra cautious and say to use 10 gauge wire because that would be more than enough. When you get into longer trailers that will end up using a lot of wire the heavier gauge wire becomes more necessary. On a smaller trailer with a single axle of brakes 12 gauge wire would probably be enough. But for a longer tandem axle trailer I would recommend you run 10 gauge wire to all the assemblies just to minimize the amount of resistance that would be on the circuit.
Also, be sure to use clean metal surfaces for your grounding locations.
Featured Help Information
Miscellaneous Media
Continue Researching
- Shop: Brake Controller
- Search Results: trailer wiring
- Shop: Trailer Wiring
- Search Results: trailer brakes
- Article: Trailer Wiring Diagrams
- Shop: etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector
- Shop: Trailer Hitch
- Search Results: trailer hubs and drums
- Search Results: junction box
- Shop: etrailer Electric Trailer Brakes - Self-Adjusting - 10" - Left/Right Hand Assemblies - 3.5K
- Search Results: wiring
- Search Results: trailer breakaway kit
- Search Results: trailer lights
- Shop: 12 Gauge 2 Conductor Jacketed (Brake) Wire Per Foot
- Shop: Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot
- Q&A: Instructions to Wire a Trailer for Electric Brakes
- Shop: Easy Grease Trailer Hub and Drum Assembly for 3.5K Axles - 10" - 5 on 4-1/2 - Pre-Greased
- Shop: 10 Gauge Wire - Blue Primary - Per Foot
- Shop: Dexter Nev-R-Adjust Electric Trailer Brakes - 10" - Left/Right Hand Assemblies - 3.5K
- Video: Review of The Headrest Safe Vehicle Locks - Vehicle Safe - HS54FR
- Video: Review of The Headrest Safe Vehicle Locks - Vehicle Safe - HS59FR
- Video: Feature Breakdown: Jacketed 2 Wire (Brake Wire)
- Shop: Truck Bed Auxiliary Tank
- Shop: Suspension Enhancement
- Article: Breakaway Kit Installation for Single and Dual Brake Axle Trailers
- Q&A: Looking For Brake Assemblies And Hubs For Dexter 4,400 lb EZ-Lube Axles
- Video: How to Install Your Curt Friction Sway Control
- Q&A: Is 14 Gauge Wire Too Small for Electric Trailer Brakes
- Shop: Tool Box
- Article: How to Measure Your Trailer Wheel Bolt Pattern

Mark C.
5/26/2025
Do you offer a 7 pin pigtail with 10g brake wire?