Could be the connections too.
When the ignition switch is in "run" the ballast resistor will drop the voltage going to the coil. More when its hot, less when its cool.
When the ignition switch is in "start" the power goes directly to the coil side of the ballast resistor. Coil should be getting system voltage - which of course is battery. Somehting like 11.5 to 12.5 depending on how much starter is drawing it down.