I have a 2005 Ford F-150 with the tow package, but I bought it used and it did not come with the trailer brake controller kit with the pigtails and relay. I purchased a Reese controller and wiring adapter, and connected that to the plugin underneath the steering column. I also purchased a trailer emulator that I can plugin to the 7 pole connector on the back, as I don't have a real trailer to test with.

With the truck on and the emulator plugged in, I don't get any green light on the brake controller that indicates it has power and recognizes that a trailer is present. I also don't see any indication that has power when I step on the brake pedal. I checked and I have fuse 105 (it's a known good fuse) that controls the trailer brake system as per the owner's manual. However, I notice that in the kit that came with the truck it includes a relay (R05) which I don't have. Do I need this relay before I will have power to my brake controller, or should I have power without it?

 

I Installed mine without thinking as I had the tow package. I thought the relay controlled the auxiliary battery charge (constant 12 volts). I thought that brake lights, tail, signal and reverse all worked without it but I could be wrong. If you're plugging in the test connector and not seeing constant power then that is likely due to the relay.

 

I'm concerned about the brake controller itself having power.

 

Nevermind...it turns out the problem was that my 7 pole connector at the back is kind of touchy. I had to push and hold the tester in, and then I got the trailer brake light on it and the correct light on the controller.