Component Tests and General Diagnostics
Magnetic Type1. Turn ignition switch to On or ACC position.
2. Connect a 10 ohm resistor between gauge lead and ground. The centerline of pointer should fall within the band around the H mark.
3. Connect a 73 ohm resistor between gauge lead and ground. The centerline of pointer should fall within the band around the C mark.
4. If gauge tests within calibration, replace sender.
5. If gauge is out of calibration, replace gauge.
Bimetal Type
The Instrument Voltage Regulator (IVR) supplies a common regulated voltage for temperature, oil pressure, and fuel gauges. The IVR is malfunctioning only if all gauges show similar problems.
Test temperature gauge with Rotunda Gauge Tester 021-00055 or equivalent or with a 10 ohm resistor for high calibration and a 75 ohm resistor for low calibration as follows:
1. Turn ignition switch to On or ACC position.
2. Connect a 10 ohm resistor between gauge lead and ground. The centerline of pointer should fall within the band around the H mark.
3. Connect a 75 ohm resistor between gauge lead and ground. The centerline of pointer should fall within the band around the C mark.
4. If gauge tests within calibration, replace sender.
5. If gauge is out of calibration, replace IVR and retest.
6. If gauge is out of calibration, replace gauge.
Refer to System Diagnosis for coolant temperature indicating system diagnosis. Coolant Temperature Indicating System Diagnosis