Low Fuel Lamp/Indicator: Description and Operation
How the Circuit WorksWhen the ignition is in ON (II) or START (III), battery voltage is supplied through fuse 5, the low fuel indicator light and parallel resistor to the thermistor in the fuel tank unit. The thermistor is grounded at G403. The thermistor has high resistance when cool and low resistance when warm. The current through the thermistor warms it. When the fuel level is above the thermistor, the fuel cools the thermistor, the resistance remains high, and the light does not come on. When the fuel level is below the thermistor, the fuel cannot keep the thermistor cool. As the thermistor warms, its resistance is lowered and the low fuel indicator light comes on.