Trailer Tow Package

I'm a bit confused and this may sound like a stupid question but if I have the trailer tow package and I hook the brake controller (Prodigy) into the factory wired plug under the dash via the correct adapter (Tekonsha 3035P), is that it? Is the circuit breaker or fuse already installed from the factory. The reason I ask is because the factory provided pigtail that comes with the car (which I don't plan on using) has tags on it for running lights and brake light.
But thats already hooked up via the factory mounted 7 pin adapter on the hitch so why would you need to splice into them again?
Basically what I'm asking is this a plug and play unit with the proper adapter (one with no splicing)?

 

[thebrakeman]

It sounds like you bought the pigtail that will connect to the underdash plug, and the Prodigy. If that's the case, then you will not need to use the factory provided pigtail.

If you had not used the pigtail with plugs on both ends, you would have:
-plugged the factory pigtail into the underdash plug (leaving 4 bare wires)
-plugged the pigtail provided with the Prodigy, into the Prodigy (leaving 4 more bare wires)
-connected those 4 sets of bare wires together to make a 2-ended harness.

By purchasing that Ford-specific harness, you saved yourself the work of connecting 2 pigtails together. That's all. Just save the factory harness in case you need it.