Ignition Cable: Description and Operation

Distributor, Exploded View:

The distributor cap is used to make the connection between the rotor and the correct spark plug wire. High tension current from the rotor is distributed to the towers of the distributor cap at a pre-set sequence and then to the spark plug wires which carry the current on to the spark plug.

The spark plug wires connect the terminals in the distributor cap to the spark plugs, allowing high voltage to flow to the spark plugs. The wires have an internal resistance, 25k ohms maximum, to suppress radio static.