INSTRUMENT PANEL, INSTRUMENTS AND CONTROLS
discharge when these items are operating and the
The instruments (Fig. 1) generally required in the
operation of a diesel engine consist of an oil pressure
engine speed is reduced.
gage, a water temperature gage, an ammeter and a
mechanical tachometer. Also, closely related and
usually installed in the general vicinity of these
instruments are certain controls consisting of an
engine starting switch, an engine stop knob, an
A mechanical tachometer is driven by the engine and
emergency stop knob and, on certain applications, the
registers the speed of the engine in revolutions per
engine hand throttle.
Marine propulsion units are provided with an
instrument panel which usually includes an engine oil
pressure gage, reverse gear oil pressure gage, water
Engine Starting Switch
instrument panels are generally mounted some
The engine starting switch is mounted on the
distance from the engine. Illuminated instrument
instrument panel with the contact button extending
panels are provided for marine applications which
through the front face of the panel. The switch is used
require night operations.
to energize the starting motor. As soon as the engine
starts, release the switch.
Oil Pressure Gage
The oil pressure gage registers the pressure of the
lubricating oil in the engine. As soon as the engine is
started, the oil pressure gage should start to register. If
A stop knob is used on most applications to shut the
the oil pressure gage does not register at least the
engine down. When stopping an engine, the speed
minimum pressure listed under Running in the Engine
should be reduced to idle and the engine allowed to
Operating Instructions, the engine should be stopped
operate at idle for a few minutes to permit the coolant
and the cause of low oil pressure determined and
to reduce the temperature of the engine's moving
parts. Then the stop knob should be pulled and held
corrected before the engine is started again.
until the engine stops. Pulling on the stop knob
manually places the injector racks in the "no-fuel"
position. The stop knob should be returned to its
Water Temperature Gage
original position after the engine stops.
The engine coolant temperature is registered on the
water temperature gage.
An ammeter is incorporated into the electrical circuit
to show the current flow to and from the battery. After
starting the engine, the ammeter should register a high
charge rate at rated engine speed. This is the rate of
charge received by the battery to replenish the current
used to start the engine. As the engine continues to
operate, the ammeter should show a decline in charge
rate to the battery. The ammeter will not show zero
charge rate since the regulator voltage is set higher
than the battery voltage. The small current registered
prevents rapid brush wear in the battery-charging
Fig. 1 - Typical Instrument Panel
generator. If lights or other electrical equipment are
connected into the circuit, then the ammeter will show