James:
If you have someone to assist you, use a 12 volt test light or multimeter on the bottom, right side pin of the female, seven pin trailer connector on the rear of your truck and have somone step on the truck's brake pedal or operate the manual lever or slide switch of the brake controller. I might be telling you the wrong pin, it could be the bottom left. The seven pin connector on your Dodge should be labeled in case I'm telling you wrong from memory. In any case, whichever pin it is, if the controller is properly installed you should show no voltage when the brake is not applied and should read 12-13 volts when the brake is applied.
Harvey