Speedometer and Odometers

With the ignition in RUN or START, 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 (VSS) sends a pulsed signal through the YEL/RED wire by switching its connection to ground on and off. The number of pulses increases with increasing speed. The ODO/ trip meter drive circuit uses this information to drive the trip and odometer stepper motors, and supplies the pulse information to the speedometer drive circuit which, in turn, controls the speedometer.