Neutral Safety Switch: Description and Operation

Fig. 7 Mechanical neutral start system:

Actuation of the ignition switch is prevented by a mechanical lockout system, Fig. 7. This prevents the lock cylinder from rotating when the transmission is out of the Park or Neutral position. When the selector lever is in the Park or Neutral position, the slots in the bowl plate and the finger on the actuator rod align, allowing the finger to pass through the bowl plate in turn actuating the ignition switch. If the transmission shift lever is in any other position, the finger contacts the bowl plate when the lock cylinder is rotated.