Gauges & Instrument Panels: Operation

Speedometer on 300SDL, 420SEL and 560SEL models is electronic, with a sending unit in the rear of the transmission. Speedometer on other models is cable driven. The 300SDL, 420SEL and 560SEL models use an electric oil pressure sending unit. All other models have an oil pressure line to the instrument cluster. Fuel and temperature gauges on all models use variable resistance sending units.

Diesel models have a vacuum switch incorporated with the ignition switch to stop engine operation. This switch controls vacuum supply to the vacuum control unit.