Amperage of Brake Magnets and Size of Wire Used To Connect 7-Way Trailer Plug To Electric Brakes
Updated 12/04/2020 | Published 07/06/2012 >
Question:
How much much amperage does each electric brake magnet require? I am trying to figure out what size wire to run from the trailer plug to the electric brakes. Thanks
asked by: Tom H
Expert Reply:
On each individual electric brake magnet the amperage draw would be 3.0 to 3.2 max amps at 12 to 13 volts on 7-inch brake magnets and 3.2 to 4.0 max amps at 12 to 13 volts on 10 and 12-inch brake magnets.
The max amperage draw for the brake magnets on a single axle trailer (2 brakes) would be 6.3 to 6.8 max amps on a 7-inch brake system and 7.5 to 8.2 max amps on 10 and 12-inch brake system. The amps will be higher if using a tandem axle or triple axle trailer.
I am including a link to a FAQ page on Electric Trailer Brake Magnets that will show you how to test them and list the numbers I mentioned above.
On a 7-Way connector the suggested minimum wire gauge for the White (ground) wire, the Red or Black (power) wire, and the Blue (brake power) wire is 12 gauge. The minimum wire gauge for the remaining Green (right turn/brake) wire, the Yellow (left turn/brake) wire, the Brown (tail lights) wire, and the Purple (reverse light) wire is 16 gauge.
Product Page this Question was Asked From
Electric Trailer Brake Assembly - 10" - Left Hand - 3,500 lbs
- Accessories and Parts
- Trailer Brakes
- Electric Drum Brakes
- LH
- 3500 lbs
- Brake Assembly
- Manual Adjust
- 10 x 2-1/4 Inch Drum
- etrailer
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Search Results: equalizer
- Search Results: spring seats
- Search Results: 19~125
- Search Results: lippert axle
- Search Results: double eye leaf spring
- Search Results: trailer door latch
- Search Results: trailer door holders
- Shop: CE Smith U-Bolt Kit for Mounting 5.2K to 7K, Round Trailer Axles - 7" Long U-Bolts - Zinc
- Shop: 6-Leaf Double-Eye Spring for 7,000-lb Trailer Axles - 24-7/8" Long
- Shop: Dexter Single Axle Standard Duty Suspension Kit - Double Eye Springs
- Shop: etrailer Electric Trailer Brakes - Self-Adjusting - 12" - Left/Right Hand - 5.2K to 7K
- Shop: Trailer Axle w/ Electric Brakes - Easy Grease - 6 on 5-1/2 - 86-1/2" Long - 6,000 lbs
- Shop: Aluminum AM03 Series Matte Black Machined Trailer Wheel - 15" x 6" Rim - 6 on 5-1/2
- Shop: 6-Leaf Double-Eye Spring for 6,000-lb Trailer Axles - 26" Long
- Shop: Brake Controller
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Shop: Trailer Wiring
- Video: This Old Trailer: Electric Trailer Brake Installation Part 1
- Video: Checking Out the Paneloc Slam Latch with Cover
- Q&A: Recommendation for Adding Third Axle To Trailer Suspension
- Q&A: Why Do Tandem Axle Trailers Need Equalizers Instead Of Independently Mounted Axles?
- Q&A: Are Shackles Necessary For A Single Axle Utility Trailer?
- Q&A: 7k Trailer Axle Needed With A 95" Hub Face And 80" Spring Center
- Video: What to Know About the Replacement Exterior Pop-Up Roof Vent
- Video: etrailer Easy Grease Trailer Hub and Drums Installation - 2020 K-Z Sportsmen Classic Travel Trailer
- Video: Let’s Check Out the Replacement Trailer Hub Bearing
- Video: Breaking Down the D Washer for EZ Lube Spindles
- Video: A Closer Look at the Stromberg Carlson Generator Storage Box for CC-255 Trailer Tray
- Shop: Trailer Hitch
- Q&A: Lug Nut Torque Chart for Trailer Wheels



Jody P.
7/10/2020
I just put a brake controller on my Mercedes suv and curious how much current the controls require. Do I need an amplifier/booster or will this drive a two axel brake system?