Function of the fuel gauge sending unit - ra47006020020x(0020)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Engines 602.96, 603.96/97 TURBO (Model 463.3: for deviations on cross country vehicles see introductory notes)

Fig 1: Identifying Fuel Gauge Sending Unit Components (Models 124, 140, 201)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Models 124, 140, 201

Fig 2: Identifying Fuel Gauge Sending Unit Components (Model 126)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Model 126

If the fuel level drops, the resistance is increased by the wiper contact (1) on the float (2), the voltage drops and the needle on the gauge in the instrument cluster moves back.

If the fuel level drops to reserve quantity, the reserve warning contact (5) closes and switches ground to the reserve warning lamp.

The reserve warning lamp lights up if the ignition is switched on (indicating function). As soon as the engine is running, it goes out provided there is more fuel in the tank than the reserve quantity.

NOTE: The reserve fuel warning lamp shows a weaker light for the indicating function and a stronger light for the reserve quantity.

Check fuel gauge (54-257).