Odometer: Description and Operation

When the ignition is in ON (II) or START (III), battery voltage is supplied through fuse 5 to the gauges in the gauge assembly.

With the ignition in ON II) or START (III), the ODO/trip meter drive circuit and the speedometer drive circuit in the gauge assembly are supplied battery voltage through fuse 5. The ODO/trip meter drive circuit applies 5 volts to the speed input terminal (YEL/RED wire). The vehicle speed sensor sends a pulsed signal through the YEL/RED wire by switching its connection to ground ON and OFF. The number of pulses increases as speed increases. The ODO/trip meter drive circuit uses this input to drive the trip and odometer stepper motors, and also supplies it to the speedometer driver to control the speedometer.