Gauge Alert Module: Testing and Inspection

Fig. 2 Gauges incorporating the LED system:

L.E.D. (LIGHT EMITTING DIODE)
The fuel, temperature and ammeter gauges are equipped with a LED (Light Emitting Diode) mounted in each of the gauge dials. This diode will illuminate and alert the driver that the system the gauge is monitoring is malfunctioning. The electronic sensor circuit is mounted on the gauge housing. The printed circuit board is permanently attached and is not serviceable. If the LED is malfunctioning, the gauge and the printed circuit board must be replaced as an assembly.




OPERATION

FUEL GAUGE
When gauge indicator shows approximately 1/8 of a tank of fuel remaining, the LED will light alerting the driver of a low fuel situation.

TEMPERATURE GAUGE
When gauge indicator shows engine temperature approximately 240 to 260 degrees F the LED will light alerting the driver of an overheat condition.

AMMETER GAUGE
This LED operates independently of the gauge indicator and monitors system voltage. The LED will alert the driver of three charging system potential malfunctions.
1. A discharging condition, caused by excessive electrical demand on charging system (engine at idle RPM).
2. A weak or defective battery with ignition switch in the "On" position, (before the ignition switch is moved to the "Start" position).
3. A weak or defective battery with minimum demand on charging system, while vehicle is being used in stop and go driving (intermittent LED illumination occurring).

TESTING

FUEL & TEMPERATURE LED
Use tester C-3826 for diagnosing systems.

AMMETER L.E.D.
Only if battery and charging system are functioning properly can the following test be performed. Turn ignition switch to the "On" position and turn on headlights, windshield wipers and stoplights. This will cause excessive demand on charging system activating the LED immediately or within approximately one minute. If the LED does not light there is a malfunction in the system. If LED lights, run engine at approximately 2000 RPM, LED should stop emitting light, if the LED continues to emit light there is a malfunction in the system. In all cases of system malfunctions the complete gauge must be replaced.