2018 express brake controller install

[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. 

 

Scott