WHY DO YOU HAVE A separate power source to the COIL between "START" and "RUN" positions of the key?
EASY. The key switch TURNS OFF the "RUN" and ACCESSORY circuits during START
This is in part so that the battery does not have to supply loads not needed during starting.....like say the heater motor
So if the RUN circuit goes dead, WHERE DOES the coil get power? EASY. From the BYPASS brown IGN2 wire during 'START'
WHY is the START and the BYPASS circuits separate at the key? EASY. Because if they were one circuit, and when the key went back to "run" the "run" power would go to the ballast, through the ballast, BACK through the brown bypass wire, and INTERCONNECT with the "start" wire, and attempt to do TtWO THINGS:
First, the backfeed from the ballast would attempt to hold the start relay engaged and run the starter
Second the power drain from the coil end of the ballast back to the starter relay would DRAG DOWN the coil voltage and only allow miserably low voltage to get to the coil
