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.
- When removing or installing the tachometer, be careful not to drop or subject it to heavy shocks.

b. Compare the tester and tachometer indications.
DC 13.5 V 20 °C at (68 °F)




If error is excessive, replace the tachometer.