Linde 633 ignition switch The ignition Switch (usually the key) is free to open or close the main circuit of the ignition coil, and also for other electrical circuits.A button or knob that starts with a key must be activated when an intelligent key is accepted, typically about 50cm.In general, smart keys also have keys that we usually call serrated or groovedIt is used to prevent the failure of aLinde 633 ignition switch key start function, and start by means of mechanical starting.A Forklift with a Linde 633 ignition switch key start function usually does not need to insert a key, but it has a location where the key is inserted (to prevent a button from starting when the key starts)