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Fuel Gauge: Description and Operation

How the Circuit Works

The indicator lights are controlled by different conditions in their associated systems. Refer to each associated system to see its entire schematic.

Fuel Gauge

The fuel gauge has two intersecting coils wound around a permanent magnet rotor. Voltage applied to the coils, through fuse 9 (in driver's under-dash fuse/relay), generates a magnetic field. The magnetic field, controlled by the fuel gauge sending unit, causes the rotor to rotate and the gauge needle to move. As the resistance in the sending unit varies, current through the gauge coils changes, moving the gauge needle toward the coil with the strongest magnetic field.

The fuel gauge sending unit's resistance varies from about 3 - 5 ohms at full to about 106 ohms at empty. When you turn the ignition switch to Lock (0), the gauge remains at the last reading until you turn the ignition switch to ON (II) or START (III) again.