According to Wikipedia.org, the definition of Ignition Switch is an switch in the control system of an internal combustion engine vehicle (car, automobile) that activates the main electrical systems for the vehicle. The ignition switch generally has four positions: off, accessories,on, and start. Some cars have two off positions, off and lock. Below picture shows the 1995 Chevrolet Camaro Ignition Switch Schematic Diagram. The ignition system consists of battery, generator, starter solenoid, battery junction block, and fusible link, and relay.