Seat Belt Systems: Description and Operation

CIRCUIT OPERATION
The Safety Belt Retractor Solenoids are operated by the Multi-function Alarm Module. When either front door is opened, the module powers the solenoids and they are energized. The solenoids then hold the Safety Belt Retractor Lock pendulums so that the motion of opening the doors does not lock the belts. The doors can be freely opened with the safety belts buckled.

The solenoids remain energized as long as a front door is open. A timer in the Multi-function Alarm Module keeps the solenoids energized for approximately one half second after the last door is closed.

Battery voltage is supplied to the Multi-function Alarm Module at all times through the CTSY Fuse. The Front Door Handle Switches are each connected to a different input to the module. When a door opens, the door switch closes to ground its input to the Multi-function Alarm Module. The module then energizes all the solenoids through one output.