What Size Wire And Circuit Breaker Should Be Used For The 12v Circuit On A 7-Way?

Updated 04/28/2026 | Published 04/22/2026

Products Featured in This Question

Curt Echo Wireless Brake Controller - 7-Way Plug-in w/ Bluetooth App - Up to 2 Axles - Proportional

(1915)

$289.95

12 Gauge Wire - Black Primary - Per Foot

(30)

$1.68

Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID

(72)

$1.36

Ring Terminal - 12-10 Gauge Wire - 5/16" Ring ID

(72)

$1.09

40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

(100)

$9.97

Question:

Trying to figure out what size wire I need to run from my seven way plug to my battery and also how many amp circuit breaker should I haveto power my item number 51180 brake control

asked by: Ron P

Expert Reply:

Hi Ron!

To get the 12v power port on your 7-Way working, you will want 12 gauge wire and a 40 amp circuit breaker (I have both listed below). This will get you needed power and protection for your Curt Echo Wireless Brake Controller # C51180.

12 Gauge Wire - Black Primary - Per Foot # 12-1-1
40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket # 9510

You will only need the one circuit breaker, but we typically say to grab at least 20 feet of the 12 gauge wire. You will probably have some left over, but it's always better to have a bit too much rather than not enough. To complete the install, you will also want to grab two of the Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID # 44-5310A for connecting to the circuit breaker and one of the Ring Terminal - 12-10 Gauge Wire - 5/16" Ring ID # 44-5356A for the battery connection.

What kind of trailer are you going to be towing?

expert reply by: Lazer S

Battery Wire Connection Example
(click to enlarge)

7heangryve7eran

4/28/2026

I bought this brake controller to work on a Cynergy cargo trailer used for my mobile mechanic business. I really like the ability to have a brake controller that didn't require me to wire up a traditional controller into the tow vehicle. The app is easy enough to use, and I like that the controller retains the programming in case that it's disconnected from blue tooth or loses power. The negative about this product is that the strap that holds the brake controller in the correct position is garbage and not even worth buying a replacement. When (not if) the strap breaks, the brake controller won't stay in the correct position and will lose it's connection with the tow vehicle. I think this product needs to be redesigned to not use a strap at all. The strap requires there to be a dust cap on your plug, so if you're cap is missing there's no way for the brake controller stay in the correct position. When the rubber strap broke, I replaced it with a reusable zip tie similar to the ones that I used in the military, but you can buy them online from Amazon. It works just fine now, but if my dust cap gets damaged/lost for any reason, the brake controller will become useless until I get a new cap. Overall it's a good product when the connection is secured with a zip tie (instead of a rubber strap).