Certain requirements must be met for an ignition coil to produce the high-voltage spark that fires an engine. Problems associated with meeting these requirements can be as simple as a corroded wire or weak battery. More complicated issues may also contribute to spark loss, but basic conditions are still the general means for good function of any ignition system. Knowing what to look for when troubleshooting ignition systems can allow proper decisions to be made when selecting repair procedures or replacement parts.
Two positions of the ignition switch provide power to the positive primary post of the ignition coil. In the “start” position, the switch energizes the starter motor, and full battery voltage is directed to the coil while the engine cranks. Once the engine starts, the switch is released to the “run” position.