Fuel Gauge

The pointer of the Fuel Gauge is moved by the magnetic fields of two coils. The coils are at right angles to each other. Battery voltage is applied to the E-Coil (empty) and the circuit divides at the opposite end of the coil. One path continues to ground through the F-Coil (full). Another goes to ground through the variable resistance of the level sensor in the Fuel Pump and Sender When the tank is low, the resistance of the level sensor is low. A large current flow passes through the E-Coil and the pointer moves toward E on the Fuel Gauge. When the tank is full, the Fuel Level Sensor's resistance is high. Less current passes though the E-Coil and the pointer moves toward F on the scale. With two coils operating the pointer, the Fuel Gauge is not affected by changes in the system's battery voltage.