PINPOINT TEST H - TEMP GAUGE ALWAYS INDICATES HOT OR COLD TEMP
Disconnect connector from Engine Coolant Temperature (ECT) sender. Connect jumper wire between ECT sensor harness connector terminals. Turn ignition on. Wait until prove-out is completed. Temperature gauge should indicate a short circuit by displaying top 2 and bottom 2 bars. If temperature gauge indicates a short circuit, remove jumper wire and go to step 3). If temperature gauge does not indicate a short circuit, go to next step.
Disconnect negative battery cable. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Unplug C1 and C2 connectors from instrument cluster. See Fig. 1 and Fig. 2 . With jumper wire connected at ECT sensor wiring connector, test for continuity between connector C1, pin No. 8 (Black/White wire) and connector C2, pin No. 23 (Red/White wire). See Fig. 1 and Fig. 2 . If continuity exists, replace instrument cluster. If continuity does not exist, inspect Red/White wire to ECT sensor and temperature gauge ground circuit for an open.
Warm engine to normal operating temperature. Measure resistance between terminals of ECT sensor. If resistance is greater than 75 ohms, go to next step. If resistance is less than 75 ohms, replace instrument cluster, then retest system.
Inspect thermostat, coolant level, etc., for proper operation. If cooling system components are defective, repair as necessary. If all cooling system components are okay, replace ECT sensor.
Monday, February 23rd, 2009 AT 3:46 PM