Ignition Coil: Description and Operation

The ignition coil, located on the left side of the engine compartment, is constructed using the principle of mutual induction to step up low (battery) voltage to high (ignition) voltage capable of firing the spark plugs. The coil consists of two windings of wire, primary and secondary, around a laminated iron core. When battery voltage flows through the outer, primary winding, a magnetic field is created. When current flow is stopped by the igniter interrupting the ground connection, the magnetic field collapses onto the secondary windings, producing high voltage in the secondary windings. Ignition wires then direct voltage to the spark plugs. The ratio of turns in the primary winding to turns in the secondary winding determines voltage multiplication.