Test G: Temperature Gauge Inoperative
NOTE:
Do NOT start this test unless directed by a symptom diagnosis in TACHOMETER, OIL PRESSURE & COOLANT TEMPERATURE GAUGES/WARNING LAMPS
under TROUBLE SHOOTING.
- Check the 10A Meter fuse located in the interior fuse panel. Is the fuse okay? If yes, go to step 4 . If no, go to next step.
- Turn key to OFF position. Replace the 10A Meter fuse. Turn key to ON position. Inspect the fuse. Does the fuse fail again? If yes, go to next step. If no, go to step 4 .
- Turn key to OFF position. Remove the 10A Meter fuse. Remove the instrument cluster. Disconnect the 12-pin instrument cluster connector. Measure the resistance of the Gray/Blue wire between the right terminal of the 10A Meter fuse and ground. Is the resistance less than 5 ohms? If yes, service the Gray/Blue wire between the interior fuse panel and the instrument cluster. If no, replace the 10A Meter fuse. Reconnect the 12-pin instrument cluster connector and then go to next step.
- Turn key to OFF position. Disconnect the temperature gauge sender connector located on the intake manifold coolant outlet. Connect Rotunda Instrument Gauge System Tester (021-00055) or equivalent between the temperature gauge sender connector and ground. Turn key to ON position. Adjust the instrument gauge system tester to the shown resistances. See Fig 1 . Is the temperature gauge working properly? If yes, replace the temperature gauge sender. If no, go to next step.
- Turn key to OFF position. Remove the instrument cluster. Disconnect the 12-pin instrument cluster connector. Turn key to ON position. Measure the voltage on the Gray/Blue wire at the 12-pin instrument cluster connector. See CONNECTOR IDENTIFICATION . Is the voltage greater than 10 volts? If yes, go to next step. If no, service the Gray/Blue wire between the instrument cluster and the interior fuse panel.
- Turn key to OFF position. Disconnect the 12-pin instrument cluster connector. Measure the resistance of the Black wire between the 12-pin instrument cluster connector and ground. Is the resistance less than 5 ohms? If yes, go to step 9 . If no, go to next step.
- Turn key to OFF position. Disconnect the 12-pin instrument cluster connector. Disconnect the center Black diode strip from the diode junction box connector located behind the instrument cluster. Measure the resistance of the Black wire between the 12-pin instrument cluster connector and terminal No. 14 of the diode junction box connector. See Figure . Is the resistance less than 5 ohms? If yes, go to next step. If no, service Black wire.
- Turn key to OFF position. Disconnect the center Black diode strip from the diode junction box connector. Measure the resistance of the Black/Red wire between terminal No. 15 of the diode junction box connector and ground. See Figure . Is the resistance less than 5 ohms? If yes, replace the center Black diode strip. See DIODE STRIPS under REMOVAL & INSTALLATION. If no, service the Black/Red wire.
- Turn key to OFF position. Disconnect the 16-pin instrument cluster connector. Disconnect the temperature gauge sender connector. Measure the resistance of the Blue/White wire between the 16-pin instrument cluster connector and the temperature gauge sender connector. Measure the resistance of the Blue/White wire between the 16-pin instrument cluster connector and ground. Is the resistance less than 5 ohms between the instrument cluster connector and the temperature gauge sender connector, and greater than 10,000 ohms between the instrument cluster connector and ground? If yes, replace the instrument cluster. If no, service the Blue/White wire.