It was very similar on my 2015. The harness was attached to the back of the little storage bin. I removed the bin, plugged the harness in to the controller, and clipped it back in place. Then I had to have it activated. I took it to a local shop and they did it for a fee. Cheaper than what the Ford dealer was going to charge. They wanted to charge one hour minimum.
Some of the Ford dealers on Ebay who sell them you can send them your VIN and they will verify which controller. I used forums like www.F150forum.com to figure it out. Quite a few people on there doing the same thing.
This is for the Ford factory controller. I didn't look in to aftermarket, but that may be what that short wiring harness is for.