This ignition switch controls the electrical power supply to the cab’s primary circuits, including the instrumentation, lighting, and auxiliary controls. It is mounted in the cab console and acts as the main power gate between the battery and the vehicle’s electrical system. A failing switch may cause intermittent power loss, failure of cab accessories to energize, or a no-start condition. The original-manufacturer component matches the factory switch’s contact geometry and key-tumbler indexing, so no adapter or wiring modification is required for installation.