Installing brake controller with tow package

[Sl95ram]

Hello thanks in advance for any help . 

I have a 2018 express cutaway that I am installing a brake controller into . It has the factory tow plug and harness. 

I found the 4 wires taped up under the floor Mat I connected them to my p3 harness . But it appears that the 4 wires do not have any power going to them . Im not sure if I need to make another connection somewhere or add a fuse . ? 

I tried adding a fuse in a couple spots where none exists in engine compartment fuse panel but it appears there are no connections for the fuse to go into . Any help would be greatly appreciated. 

 

[Jsdirt]

I haven't got within 500' of a 2018 model year of any brand ... but on my '07, and going forward as far as 2012 (as far as I know),  you had to locate a red wire taped up in the harness under the brake booster (has a ring terminal on the end), install a 40A J-case fuse, and connect that ring terminal to the power stud on the underhood power distribution panel (AKA, fuse box).

 

This trailer parts website has some of the best tutorials out there - that's how I hooked up my Teconsha P3 about  10 years ago. Here's a video of a 2017 GM truck install - looks even more simple than 10 years ago - I'd imagine yours shouldn't be much different:

 

 

[Doug_Scott]

On my 2010 I thought I had two wires to connect under the hood, both wires were already there, but not connected to the fuse box.  There were two studs, and both wires had ring connectors on them, two different sizes so you could not connect them wrong.  The 40amp fuse was optional, it was used if your trailer needed a 12v feed.  I would think that if your trailer has electric brakes you would need that fuse to recharge the brake battery though.

[Jsdirt]

On mine, the stud had no power without the 40A fuse.