Fuel Gauge

The pointer of the Fuel Gage is moved by the magnetic fields of two coils. The coils are at right angles to each other. Voltage is applied to coil F from the IG Fuse. The circuit divides at the opposite (ground) side of the coil. One path seeks a ground through coil E to G105 and the other path seeks a ground through the variable resistor in the Fuel Gage Sending Unit.

When fuel level is low, resistance in the Fuel Gage Sending Unit is high. Since current will always seek the path of least resistance, current will flow through coil F and coil E to ground at G105. Because the length of the E coil winding is twice the length of the F coil winding, the magnetic field generated by the E coil is twice as strong as the magnetic field generated by the F coil. Therefore, the pointer will be pulled to the "E" position.

As fuel level increases, resistance in the Fuel Gage Sending Unit decreases. Since current will always seek the path of least resistance, more current will begin to bypass the E coil and travel directly to ground through the Fuel Gage Sending Unit. Under these conditions, the coil F magnetic field becomes stronger than the coil "E" magnetic field and the pointer moves toward the "F" position.