The grease on the contact points inside the ignition switch is not of the right type, and therefore, when the ignition switch is operated slowly, arc discharge duration may become longer, and the temperature of the contact points may rise, which could cause the grease to harden. If this kind of operation is repeated, cuprous oxide is generated on the contact points, and electrical continuity may be lost at the contact points. If this occurs, (1) and if electrical continuity is lost at the contact points due to vibration while travelling, the engine would stop and would not restart, or (2) the contact points may heat up, and the heat may melt the solder behind the contact pints, and in the worst case, the melted solder might fall on a foot of the driver, causing burn.
