Tachometer: Testing and Inspection

INSPECT TACHOMETER (ON-VEHICLE)
a. Connect a tune-up test tachometer, and start the engine.

NOTE: Reversing the connection of the tachometer will damage the transistors and diodes inside.




b. Compare the tester and tachometer indications.
RPM (DC 13.5 V, 25 °C / 77 °F)

If error is excessive, replace the tachometer.