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.
Product Page this Question was Asked From
Hopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 7 Blade
- Plug and Lead
- Hopkins
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Brake Controller
- Search Results: wiring
- Search Results: trailer wiring
- Search Results: trailer brakes
- Shop: etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector
- Search Results: trailer breakaway kit
- Search Results: wire
- Shop: Suspension Enhancement
- Shop: etrailer Electric Trailer Brakes - Self-Adjusting - 10" - Left/Right Hand Assemblies - 3.5K
- Search Results: hitch anti~rattle
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Search Results: trailer hitch
- Shop: 10 Gauge Wire - Blue Primary - Per Foot
- Shop: etrailer Electric Trailer Brakes - Self-Adjusting - 12" - Left/Right Hand - 5.2K to 7K
- Shop: Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot
- Shop: 12 Gauge 2 Conductor Jacketed (Brake) Wire Per Foot
- Q&A: Is 14 Gauge Wire Too Small for Electric Trailer Brakes
- Video: Review of Dexter Trailer Hubs and Drums - Hub and Drum - DX62KR
- Video: Review of CURT Trailer Wiring - Trailer End Cold Weather 7 Way RV Style Connector - C23RJ
- Q&A: Parts Needed to Add Electric Brakes to a 2025 Stehl Tow Car Tow Dolly Model ST80TD
- Video: Redarc Tow-Pro Electric Brake Controller Mounting Kit Breakdown
- Video: Installing the Redarc Tow-Pro Liberty Brake Controller on a 2017 Toyota Highlander
- Video: Review of Kenda Trailer Tires and Wheels - Tire with Wheel - KE65EV
- Video: Installation of the etrailer Trailer Hub and Drum Assembly AKHD-545-35-K
- Q&A: Difference Between Kenda Karrier K03 and KR35 Trailer Tires
- Video: Install: 7-Way RV Upgrade Kit for Trailer Brake Controller Installation on a 2023 Toyota Highlander
- Q&A: Why is 10 or 12 Gauge Wire Recommended for Electric Brake Assemblies
- Q&A: Which Wire Sized Should be Used for Electric Trailer Brakes
- Q&A: What is the Proper Gauge Wire for Installation of a Brake Controller and Trailer Brakes
- Q&A: Recommended Hubs And Brakes For A Lippert 7,000 lb Axle
on Trailer Wiring
Mark C.
5/26/2025
Do you offer a 7 pin pigtail with 10g brake wire?