Ok, My trucks has a bumper hitch, and it has the four prong plug< I am assuming this means it has a towing package, it also has the button on the shifter that says "tow/haul"

I bought a brake controller, also bought the quick connect that is supposed to plug in under the dash...andybody know where the plug under the dash is supposed to be?

 

The harness is found loosely stuffed under the dash above the driver's right leg, it might be found attached to a module above the driver's left leg. The harness is often blue. Simply connect the brake controller harness connector into the vehicle connector. Zip tie the harness wires to another harness to prevent the wiring from hanging down near your feet.

 

If it only has the 4 prong plug, it might not be factory. I have the factory towing package and it has the four prong plug as well as the 7 prong plug. The 7 prong is what allows the brakes to hook up. Just as Eimer stated, the plug should be under the driver's dash. If yours does not have the 7 prong, it might not have the quick connect near the driver and you may have a bit more wiring to do.