Battery voltage is continuously applied to the ignition key warning switch through the tail dome fuse. When the ignition key is inserted into the ignition cylinder, the ignition key warning switch closes and a voltage signal is provided to the audio alarm module. If the left front door is open, the left front door jamb switch closes, providing a ground signal to the audio alarm module. Upon receiving the signals, the audio alarm module activates the ignition key warning alarm (approximately 2 pulses per second).

Battery voltage is continuously applied from the tail dome fuse to the headlamp relay 2. When the headlamp switch is in the PARK or the HEAD position, ground is provided for the coil in the headlamp relay 2, through the combination switch, to G201. This energizes the coil, closing the contacts in the headlamp relay 2, providing battery voltage to the audio alarm module. A voltage signal is received by the audio alarm module from the ignition coil meter fuse if the ignition switch in either the ON or the START position. If the audio alarm module receives a lights ON signal and a door open signal, but no ignition key signal, the audio alarm module activates the headlamp warning alarm (approximately 1 pulse per second).

The audio alarm module and the seat belt indicator receive battery voltage through the ignition coil meter fuse when the ignition switch is in either the ON or the START position. If the driver's seat belt is not buckled, a ground path is provided to the seat belt indicator and the audio alarm, through the closed contacts in the seat belt switch, to G300. When the signals are received, the seat belt indicator lights and the audio alarm module activates the seat belt warning alarm (approximately 2 pulses per second) for approximately 6 seconds.