Beginning January 1, 1972, all cars are required to have a warning system which operates a buzzer and a warning light if either the driver's or the front passenger's seat belts are not fastened when the seats are occupied and the car is in forward motion.
On Chevrolet products, this system consists of seat belt retractor switches, pressure sensitive front seat switches, a parking brake switch (manual transmission), or a transmission switch (automatic transmission), a warning light, and a buzzer.
The seat belt warning system is wired through the 20 amp "Gauges" fuse.
The warning light is located in the instrument cluster; and the buzzer, which is shared with the ignition key warning system, is taped to the instrument cluster wiring harness.
The warning system is activated when the ignition switch is ON, the front seats are occupied, and the seat belts are left in their retractors. Only when the front seat belts are extended and properly fastened will the warning light and buzzer stop.