G 2500 3/4 Ton Van V8-305 5.0L VIN M SFI (1997)
Speedometer Head: Description and Operation
The instrument cluster contains a high-torque type electric speedometer. The electro-mechanical gages are individually plugged into socket-type metal
connectors in the cluster case. Integrated circuits control the air core speedometer and stepper motor odometer. Lighting is provided by a removable bulb
and socket assembly that inserts into the back of the instrument cluster.
The speedometer system consists of the instrument cluster, Vehicle Speed Sensor Buffer (VSSB), Vehicle Speed Sensor (VSS), and related wiring.
The one-piece instrument cluster mounts in front of the driver in the instrument panel and is not serviceable. If diagnosis leads to a malfunctioning
instrument cluster, it must replaced or repaired by an authorized service center.
The Vehicle Speed Sensor (VSS) is a permanent magnet signal generator that sends an analog signal proportional to the propeller shaft speed to the
vehicle control module on gasoline engines or to the VSSB on diesel engines. The VSS mounts to the transmission tailshaft extension housing.
