Quote Originally Posted by Xnke View Post
"Back in the day" the ballast resistor was not in circuit during starting, but only was switched into the circuit during running conditions to prevent coil overheating. During starting, the resistor was switched out and the full 12 volts was applied to the coil-not the 8 to 9 volts that the ballast resistor provided.
I'm thinking the starter "R" terminal is the source for the coil when the ballast resistor is bypassed? Usually the voltage available with the starter spinning the engine is less than 12 volts. I'm thinking the available voltage is maybe in the range of 10.5 volts when the starter is spinning the engine, The stater motor is a HUGE draw on the available battery voltage.

dave w