Your truck is not "factory pre-wired" for a brake controller, so you will need to hardwire the controller.
Here is what you do: buy about 30 feet of 10 guage wire (15 feet of one color and 15 feet of another, preferrably red and blue wires), two 30 amp auto-resetable circuit breakers (little silver boxes with a mount tab on them and two posts for the wiring), a handfull of wiring connectors, a 7-way plug for the back of your truck, and a brake controller. You will need to run one 10g power wire from the battery (+) through one 30amp breaker (which I usually mount to the firewall) and run that wire all the way back to the rear of the vehicle. This will be the charge line for the trailer's 7-way plug. I would use the red wire for that. Second, you will need to run another 10g wire (red again) from the battery (+) through another 30amp breaker, this time going through the firewall to the main power feed of the brake controller (usually a thick red wire on the controller). Last, you will need to run your 10g blue wire from the same brake controller location, all the way to the rear of the vehicle where you will install the 7-way (I usually go back through the firewall in the same location the power feed was routed). Now you have all your wires for hooking up the brake controller.
Dont actually connect your red wires to the battery (+) until all other wiring is absolutely completed. This will prevent shorts while you are working on the wiring.
The brake controller should have four wires. The first is a large red wire. Connect this to your power feed from the battery (+). The second is a large, usually white wire; this is the ground and should be connected to the chassis ground. There is usually a ground junction just under the dash somewhere that you can use. Third is the large brake wire which is usually blue. Connect this with your blue wire that you ran to the rear of the vehicle. Last, there should be a wire that is thinner than the other three that is marked as the signal wire. This will need to be connected to the brake pedal signal. In your vehicle, there are multiple wires coming from/to the switch at the brake pedal. Use a 12v test light and find the wire that energizes only when the pedal is depressed. I usually connect the brake control signal wire into this wire using a Scotch Lock connector. That should do it for your brake controller!
Now for the 7-way plug. I would advise you buy the 4-way plug in the picture above, plug it into your truck as recommended, and tap into those wires. This way you will not be cutting the factory Ford wiring, just the added harness wires. I would also advise you use heat-shrink butt connectors to prevent corrosion, or better yet, solder the connections and use heat shrink and electrical tape over the soldered connections. Last, I would advise you get a 7-way for your truck that has the wires already connected to it, not just the plug.
7-way wiring if you buy the one with wires already connected:
1) blue brake wire (connect to blue from brake controller)
2) black charge line (connect to red from the battery +)
3) white ground wire-run this from the plug straight to a ground point on the chassis
wires to connect to your 4-way harness pictured above:
4) right turn signal
5) left turn signal
6) marker lights
Other:
7) yellow wire for reverse lights - connects to the center pin of the 7-way, but is not needed if your trailer does not have reverse lights.
Check out this page if you need help with wire color codes:
http://www.marksrv.com/wiring.htm
