Tachometer: Description and Operation

When the ignition switch is in ON (II) or START (III), battery voltage is supplied through fuse 1 to the gauges in the gauge assembly. The gauge circuit is grounded at G404.

The tachometer drive circuit receives pulses from the ignition control module (ICM) in the distributor assembly (2.2L models) or from the ECM or PCM (All except 2.2L models). The solid-state tachometer then displays these pulses as engine speed. For each 200 pulses per minute from the ICM, the tachometer displays 100 RPM.