Quantity: Set of 4 Kits. The Ignition Coil is located near the distributor in older applications, on top of the ignition control module in distributor-less ignition systems or as a coil-on-plug or coil-near-plug in. For What: The Ignition Coil supplies the needed voltage required to fire the spark plug and complete the ignition cycle. The secondary output voltage from the ignition coil is generated when the voltage in the ignition coil primary circuit is momentarily shorted to ground and then open circuited. The magnetic field within the coil collapses when the circuit opens ...