Distributor

On older engines where a direct ignition system (DIS) is not used, an ignition distributor is present. This component uses a rotor attached to a driveshaft, which spins with the camshaft (in most cases) underneath a distributor cap. In a distributor ignition system, the ignition coil, having received a signal from the points and condenser or electronic control module, sends voltage through a coil wire to the center of the cap. The voltage then jumps down to the middle of the rotor and out to its end. From here it jumps back up to the outer part of distributor cap, through the spark plug wire connection it is directly under. Finally the voltage travels through the spark plug wire and ends at the spark plug, where it is converted into a spark required to ignite the fuel and air mixture. An electronic ignition distributor uses an ignition module to control when the coil fires and sends voltage to the distributor, while points and condenser-equipped distributors complete this process mechanically.