Voltage drop at ballast resistor

What do you get at the battery with ignition on and with ignition off?
What loads are on when the ignition is on? (radio, Electronic ignition, etc)

My recollection.... (I'm old so take it for what you will) is that the coil really wants to run at ~6V. when the car is starting you bypass the ballast resister and provide 12V to the coil for a short amount of time. after starting the coil voltage goes through the ballast resister and you end up with about 6V. If you are starting at 10.5 and subtract 6V you get 4.5V.

Seems about right might be a weak battery at this point.

does it run?