Tachometer: Testing and Inspection

1. Get the J33431 Instrument Panel Cluster Tester (or equivalent) and connect the J33431-10 harness connector to the J33431.
2. Disconnect the connector to the Ignition Module which contains the Tachometer wire.
3. Connect the black lead of the J33431-10 to ground and the red lead to the Tachometer lead of the Ignition Module Connector.
4. Plug the J33431 into a nearby 120 volt outlet.
5. Set the Tester Frequency Signal Switch to 60 Hz and Power switch to ON.
6. Put the vehicle Ignition Switch in RUN and observe the Tachometer.

^ If the Tachometer shows 1350 rpm (6 cyl) or 1800 rpm (4 cyl), replace the suspect Ignition Module.
^ If the Tachometer does not operate, check the wire to the Tachometer for an open or short to ground. Check that the Instrument Panel Cluster Connectors and the screw connections at the back of the Cluster are clean and tight. If all of the above are OK, replace the Tachometer.