LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 1999 >> Forward Control 6.5 Y, Standard >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel - Analog - G Series >> System Tests >> Temperature Gauge Is Inaccurate

Temperature Gauge Is Inaccurate

  1. Warm engine to normal operating temperature. Compare engine temperature with coolant gauge reading. If readings are within 30 degrees of each other, gauge is operating properly. Check cooling system. If readings are not within 30 degrees of each other, go to next step.
  2. Disconnect coolant temperature sender harness connector. Using Tester (J-33431-B), connect Red tester lead to Dark Green wire terminal of temperature sender harness connector and other lead to ground. Adjust tester to 1305 ohms and check temperature gauge. Adjust tester to 49.5 ohms and observe temperature gauge. If temperature gauge indicates approximately 100 degrees and then approximately 260 degrees, replace coolant temperature sender. If temperature gauge does not indicate approximately 100 degrees and then approximately 260 degrees, go to next step.
  3. In previous step, if temperature gauge indicated significantly below hot at 49.5 ohms, go to next step. If temperature gauge did not indicate significantly below hot at 49.5 ohms, replace instrument cluster. See INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION.
  4. Disconnect instrument cluster harness connector. Using ohmmeter, measure resistance between instrument panel harness connector terminal No. B9 (Dark Green wire) and temperature sender harness connector. If resistance is less than 20 ohms, replace instrument cluster. See INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. If resistance is more than 20 ohms, repair Dark Green wire.
scientia non olet · About LEMON Manuals