The coil needs voltage that it gets from the starter relay (solenoid). It comes from the small top post nearest the starters wire, when turning the engine over. The voltage next comes from the ignition switch through a resistive wire or ballast resistor after you get it to fire up. Then the coil needs the switched ground from the points. Burnt points would prevent a spark. A shorted condenser would prevent a spark also. An open coil would prevent spark. After that, your into the high voltage side of things. Coil wire, cap, rotor, plug wires, and plugs.