Fuel Gauge Sender: Description and Operation

Battery voltage is supplied to the gauges from the METER fuse in the passenger compartment fuse box when the ignition switch is in ON or START.

A float attached to a variable resistor is mounted in the fuel tank. With a full tank, the float arm sits at the top of the tank and the variable resistance value is high. As the float drops, so does the resistance value. The sender operates the fuel gauge.