I'm not sure this is it. For some reason it didn't post or went away
This may be it or similar. If you have a 2 pin ballast, just ignore everything vertically on the left side of the ballast.
Everything blue is IGN1 "ignition run" or switched 12V in the run position of the key. The brown is the bypass circuit, IGN2, and is hot only in "start" just like the yellow "start" circuit.
The coil side of the ballast circuit works exactly like and is wired exactly like a breaker points set up.