Hey guys! I noticed this red wire a while back, wondering what it is? Does anyone else have this? Or did some mechanic get lazy and I never caught it? Haven't had any work done where I would think they need to get to the fuse box. The fuse is removed for the washer fluid heater but that't it. Also no after market accessories on the truck.
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Those are the factory wires for your trailer brakes.
They are normally not connected to the fuse box from the factory and only get hooked up if you are installing a trailer brake controller.
One wire feeds power to the inside of the truck for the controller (4 blunt cut wires taped under the drivers side of the dash above pedals).
The other wire feeds power to the 7 pin connector out back to keep your emergency trailer brakes battery (break away switch) on your trailer charged.
From the factory one is taped to the harness under the master cylinder and the other is taped up between the fuse box and fender.
They have different sized ring terminals on each wire and the 2 studs at the front of your fuse box are different sizes as well so you can only hook the proper wire to the proper terminal.
They can be disconnected and rerouted under the fuse box if you would like for cosmetic reasons.
