Video narration
How does a spinning distributor send a spark to the right plug? Like a bicycle dynamo, turning creates an electrical signal. A reluctor, a toothed trigger, passes a magnetic pickup, a nearby sensor. Changing magnetic flux creates a small AC pulse, marking when the engine should fire. But that pulse is not the spark's high voltage. It tells the igniter, an electronic switch, to control current in the coil's primary winding. Switching that current off collapses the coil's magnetic field, inducing high voltage in its secondary winding. The distributor rotor, a spinning contact inside the cap, routes that voltage through the cap to the aligned terminal, then to that cylinder's spark plug. The spark ignites the compressed air-fuel mixture. So how does it reach the right plug? The reluctor sets the timing; the igniter switches coil current, and the rotor routes high voltage to that cylinder's plug.