Instrument Panel - Standard: Operation
The speedometer on 300SD, 380SEL and 500SEL models is electronic, with a sending unit in the rear of the transmission. All other models use a cable-driven speedometer. The 300SD, 380SEL and 500SEL models also 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. Vacuum gauges are connected directly to the intake manifold by a vacuum line.
CAUTION:
On models with Supplemental Restraint System (SRS), observe the following precautions: Before any repairs are performed, disconnect and shield battery ground. Disconnect 10-point SRS connector under passenger's foot rest. Use extreme caution when working around steering column. Models with SRS may be identified by a SRS light below tachometer.