Fuel Gauge: Description and Operation

When the ignition is in ON (II) or START (III), battery voltage is supplied through fuse 5 to the gauges in the gauge assembly.

The fuel gauge is operated by two intersecting coils wound around a permanent magnet rotor, and a bucking coil in series with the full coil. When voltage is applied to the coils, a magnetic field is generated which causes the rotor to rotate and the gauge needle to move. The magnetic fields are controlled by the fuel gauge sending unit in the fuel tank. As the resistance in the sending unit varies, current through the gauge coils changes, and the gauge needle moves according to the changing magnetic field. When you turn the ignition switch to Lock (0), the needle remains at the last reading until you turn it ON again.