Fuel Gauge

The pointer of the Fuel Gauge is moved by the magnetic fields of two coils, the E Coil and the F Coil. The two coils are oriented at right angles so that the magnetic fields interfere with each other. Battery voltage is available from GAUGES Fuse 4 through the PNK (39) wire to the Instrument Cluster when the Ignition Switch is in Run or Start. Current flows through the E Coil which places the pointer at E (empty) if there is little current through the F Coil. If the current through the F Coil is high, then the pointer moves toward the F (full) indication.

The current that passes through the E Coil has two paths to ground. Some of the current can pass through the fixed resistance of the F Coil and to Ground G101 through the BLK/WHT (451) wire. The rest of the current will go to ground through the variable resistance of the fuel sender element. The fuel sender element in the Fuel Pump and Fuel Sender (Gasoline Engines) or in the Fuel Tank Level Sender (Diesel Engines) produces a resistance of approximately 4 ohms when the fuel tank is empty. With this low resistance, most current passes through the fuel sender and not the F Coil. If the tank is full, then the fuel sender's resistance is approximately 90 ohms. With this high resistance, more current flows through the F Coil and the pointer moves to F.

The Fuel Gauge's accuracy is adequate for normal operator usage in that it provides a reasonably accurate indication of level in the fuel tank. Gauge accuracy is not affected by changes in battery voltage. However, the accuracy of the Gauge can be influenced by non-linear construction the fuel tank and by the motion of fuel in the tank.