Normal Operation
WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
When the key is inserted into the ignition cylinder, the key-in-ignition switch (part of the ignition switch) closes. The 12 volt input signals the instrument cluster that the key is inserted. If the instrument cluster detects that the ignition switch is in the OFF or ACC position with the key inserted in the ignition cylinder and the driver door is ajar, the key-in-ignition warning chime (located in the instrument cluster) sounds.