Where Does the Blue Brake Controller Wire Connect to on a 6-Way Round Trailer Connector

Updated 08/20/2025 | Published 03/27/2011

Question:

i read that the blue wire needs to go from the controller to the trailer. so what do i hook the blue wire to??

asked by: Perry

Expert Reply:

The blue wire is for brake output power to the trailer brakes. One end connects to the brake controller and the other end goes to the pin in the trailer connector on the vehicle side that is for the trailer brakes. The Adapter 6 Pole to 7 Pole Trailer Wiring Adapter, # 47435, would be if your towing vehicle has a 6-Way round pin trailer connector and the trailer has a 7-Way blade style trailer connector.

In this case, on the truck, the brake pin would be in the 2 oclock position, if looking at the back of the plug. I have included a link to a wiring FAQ that shows the various types of connectors and how they are wired on a trailer and on a tow vehicle.

expert reply by: Michael H

Donald S.

6/11/2020

I have a 2011 pathfinder that I need to wire the brake controller into. I dont have a harness to go connect to the controller so I can plug it directly into the pathfinder. So what I need to do is tap into the wires on the pathfinder harness from the controller (I know this is not ideal however time is an issue). The wires coming off of the controller are Blue, White, Red and Black. The question is what wires do they match up to on the pathfinder

Jacob H.

6/15/2020

If you have a factory tow package on your vehicle, you can use part # 3050-P to plug directly in your connection under your dash. If the connection to your brake controller is not the same as what is on this harness, I would recommend cutting on the adapter and not on your factory wiring.

Helpful Links

accessories-and-parts/tekonsha/3050-p.html

Donald S.

6/16/2020

@JacobH Next question. I bought a 2017 Forest River Flagstaff 625d classic popup. I would like to purchase a stabilizer/weight distribution system. The only spot on the tongue of the trailer that I can connect the back part of the bars is 38-40 inches away from the ball. Do you know what model of system I would need?

Chris R.

6/19/2020

@DonaldS That's too far of a reach for any of the WD systems we have available. Your best option will be to use a chain-type system with Chain Hangers # RP58305 that can be bolted to the side of the A-Frame (which will avoid any interference with that propane tank). For a specific setup I recommend the Reese Strait-Line # RP66083.

Bryan S.

8/20/2025

I have a 2003 Suburban. The brake lights do not come on with the brake pedal. The brake light switch has power leaving it when the brake pedal is pressed. The suburban has yellow turn signals. There is no power for brake lights at the blue plug on the combination brake light circuit board at the rear of the vehicle behind the passenger rear wheel. Park lights etc have power coming to that blue plug. There trailer brake controller is plugged into the factory board up behind the emergency brake pedal. The trailer brake controller will activate the brake lights. Every fuse I have found has been good. It’s like there is a disconnection between the output on the brake light switch and whatever feeds the blue plug in the back. I am unaware of any intermediate plug or board The suburban has yellow turn signals, so it doesn’t seem like it would need to go from the brake pedal switch to the turn signal controller on the steering column and then to the rear. Any help is appreciated.

Jameson C.

8/20/2025

@BryanS Check the third brake light to see if it lights up when you hit the brakes. Most of the time this issue with your generation of Chevy vehicle is a blown third brake light or CHMSL fuse.