During normal operation, the coil gets 7-8 volts through the cloth-covered resistance wire that feeds it from the ignition switch, which improves point life. During cranking while starting, the wire from the "R" terminal on the solenoid to the (+) coil terminal feeds a full 12 volts from the solenoid to the coil, bypassing the resistance wire, providing more voltage to the coil for starting. When the engine starts and the solenoid disengages, the coil (+) is again fed by the resistance wire.