To check the voltage drop across the ballast resistor, the points MUST be closed, engine stopped, ignition in the "run" position. If the points are open there's no current flow, and no voltage drop across the resistor. Normally, 12V into the resistor will yield about 9 to 9.5 volts at the coil + terminal with the points closed.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!