Fuel Gage

The pointer of the Fuel Gage is moved by the magnetic field of two coils. The coils are at right angles to each other. Battery voltage is applied to the E coil and the circuit divides at the opposite end of this coil. One path continues to ground through the F coil. The other path grounds through the variable resistor of the Fuel Gage Sender.

When the tank is low, the resistance of the sender is low (0 ohms). A large current passes through the E coil and the Fuel Gage Sender resistor. This moves the pointer toward "E" on the scale. When the tank is full, the sender resistance is high (90 ohms). More current flows through the F coil, moving the pointer toward "F" on the scale.

With two coils operating the pointer, the gage is not affected by changes in the voltage of the system.