Tachometer: Description and Operation

When the ignition switch is on ON (II) or START (III), battery voltage is supplied through fuse 13 to the gauges in the gauge assembly. The gauge circuit is grounded at G401.

The tachometer drive circuit receives pulses from the Ignition Control Module (ICM) in the distributor assembly. The solid-state tachometer then displays these pulses as engine speed. For each 200 pulses per minute from the ignition control module (ICM) the tachometer displays 100 RPM.