Seat Belt Systems: Description and Operation

AUTOMATIC SEAT BELTS OPERATION
Battery voltage is applied to the seat belt controller at all times through the tail Fuse. Battery voltage is also applied through the IG Fuse when the ignition switch is in the "ON" or "START" position. The automatic seat belts operate when the driver or passenger is seated, seat belts are fastened, and both doors are closed. Should either door open or seat belt come unbuckled, a signal voltage is sent from the seat belt controller through the door switches, door latch switches or seat belt switches to ground. This signal activates an electronic relay in the seat belt controller which energizes the belt retractor solenoids. When the belt retractor solenoids energize, the seat belt locking mechanisms are disabled.

DOOR OPEN INDICATOR
The seat belt controller also provides a ground for the Door Open Indicator when it receives a door open signal from either door switch. When the seat belt locking mechanisms are disabled, the seat belt controller provides a ground for the seat belt indicators. These indicators war the driver that the seat belt locking mechanisms are disabled and that the seat belts cannot provide restraint capability. The seat belt controller also contains an alarm that activates when the seat belt locking mechanisms are disabled.

SEAT BELT INDICATORS
The Seat Belt Indicators will also light when the ignition switch is in the "START" or bulb test position and the seat belt controller senses a ground through the ignition switch.