Mercedes-Benz Car Ignition Switch

The lock cylinder is the mechanical part operated by the key; the electrical ignition switch controls circuits. Some vehicles use separate parts, so replacing the switch alone is different from replacing the keyed cylinder.

On many conventional keyed systems, Start is held only while the engine is being cranked. The key then returns to On or Run when released, allowing normal operation.

A discharged battery or poor battery connection can prevent normal cranking even if the ignition switch works. Check battery condition and the starting circuit before selecting a switch.

Terminal count is only one detail. The connector shape, mounting and circuit arrangement must suit the application; the collection includes different six-, seven- and eleven-terminal designs.

The need depends on the vehicle and which components are replaced. An electrical switch and a coded lock cylinder are distinct parts; follow the applicable service procedure for any required key learn or security steps.