Engine will not start

Hey FABO, I'm having trouble with my 1968 dodge dart. Me and my dad bought the car running, but now it wont start. We believe this part might be the problem, the picture is included below. There is a wire that runs off of it that just ends, we cant find it in any wiring diagram, and we cant find what it is suppose to hook up to. Any idea what the part is and what it does?