Fuel Level Indication System
The fuel level indication system is a magnetic gauge system. It consists of a magnetic fuel gauge (9280) mounted in the instrument cluster (10849) and a sending unit located in the fuel tank (9002) with an instrument cluster gauge amplifier (10E849) in series between the two. No instrument voltage regulator is used with this system.
The magnetic gauge movement consists of three primary coils, one of which is wound at a 90-degree angle to the other two. The coils form a magnetic field which varies in direction according to the variable resistance of the sender unit which is connected between two of them. A primary magnet, to which a shaft and pointer are attached, rotates to align to this primary field, resulting in pointer position. The bobbin/coil assembly is pressed into a metal housing which has two holes for dial mounting. There is no adjustment, calibration or maintenance required for these gauges. The instrument cluster amplifier is calibrated to the fuel gauge. The instrument cluster amplifier and fuel gauge must be replaced as a system.
Instrument Cluster Gauge Amplifier/Check Gauge Module
The instrument cluster gauge amplifier electrically averages fuel sender readings so the fuel gauge displays actual fuel level and not fluctuations due to sloshing in fuel tank. The instrument cluster gauge amplifier is a small printed circuit board which latches into a pocket on the back of the instrument cluster. The electrical connections for ignition, ground, input from fuel sender and output to fuel gauge are made through a spring-type connector on the instrument cluster gauge amplifier to the instrument cluster printed circuit (10K843) on the instrument cluster. There are no provisions for calibration or adjustment of the instrument cluster gauge amplifier.
Fuel Sending Unit
The fuel sending unit consists of a variable screened resistor made up of a ceramic substrate. It is controlled by the action of an attached float in the fuel tank. When the fuel level is low, resistance in the sending unit is low. When the fuel level is high, the resistance in the sending unit is high. As the float moves from empty to full, the resistance will gradually and continuously increase.