no power to key..........

I'm working on a 76 Duster and can't get any power to the key. When I leave the key in the on position for 5 minutes or so the ballast gets real hot and so do the wires next to it. I can make the starter spin by jumping it right at the starter but it won't spin if I jump it on the starter relay on the fender. There is power TO the relay. Any advice?? Also, which side of the coil does the "HOT" wire go? Also, do one of the small wires that come from the starter relay on the fender go straight to the starter? The big one comes from the battery and then there are two plastic plug-ins but the fourth one that is held by sliding it in behind the little screw,,,where does that one go? I have a loose wire that's the same color as the one on the relay but don't know where it goes.