Komatsu 830E, Shop Manual

Page: 141 / 783

D03026 24VDC Electrical System Components D3-1
24 VDC ELECTRICAL SYSTEM COMPONENTS
PASSENGER SEAT BASE
COMPARTMENT
The 24 VDC electrical system components shown in
Figure 3-1 are accessed by unlatching the passenger
seat base lid and tilting the passenger seat forward.
The electrical schematics in Section R should be
used when troubleshooting problems with the follow-
ing components.
COMPONENTS
TAIL LIGHT RESISTOR DIODE ASSEMBLIES
The tail light resistor diode assembly RD1, RD2 (2,
Figure 3-1) is a circuit designed to vary the intensity
of each of the stop/tail lamp bulbs.
With the tail lights on, a resistor in series with the
lamp reduces voltage supplied to the lamp, thereby
reducing the lamp intensity. When the service brakes
are applied and the stop lights are activated, current
flows from the stop light relay, through a diode,
bypassing the resistor and applies 24 VDC to the
lamp filament.
RD1 controls the left lamp and RD2 controls the right
lamp. No adjustments are available or necessary.
INCLINOMETER
The inclinometer (8) is used by the on-board load
weighing system to determine whether the truck is on
a level surface or tilted fore or aft. The information
provided by the inclinometer is sent to the weighing
system for use in calculating the payload. Refer to
Section M for detailed information on the inclinome-
ter and on board load weighing system.
BRAKE WARNING BUZZER (BWB)
The brake warning buzzer (11) provides an audible
alarm for the operator if a malfunction occurs in the
hydraulic service brake system. Refer to Section J for
additional operational details.
LUBRICATION SYSTEM TIMER
Automatic Lubrication System lubrication interval is
controlled by the timer (17, Figure 3-1). Lubrication
cycle frequency can be adjusted by removing the
timer cover and selecting one of five different timing
intervals available. System “on” time is automatically
determined by the timer and is not adjustable. Refer
to Section “P” for additional automatic lubrication
system details.
5 MINUTE IDLE TIMER COMPONENTS
The 5 minute idle timer circuit automatically provides
approximately 5 minutes engine idle time before
actual engine shutdown occurs. This system allows
the engine cooling system to circulate coolant to
reduce and stabilize engine component tempera-
tures, when engine power requirements are minimal,
resulting in extended engine life.
The circuit is controlled by a 3-position rocker switch.
Pressing the bottom of the switch will turn the circuit
OFF. The engine will shut down by use of the Key
Switch, console mounted Engine Shutdown Switch,
or the Ground Level Shutdown Switch.
With the rocker switch in the middle position, the cir-
cuit is ON, but does not activate the 5 minute idle
timer circuit. The engine can be shut down immedi-
ately using any one of the three switches described
above.
When the top of the switch is depressed and held
momentarily, the idle timer circuit is activated. At the
same time, the operator must turn the keyswitch to
the OFF position. When released, the rocker switch
will return to the ON (middle) position, and the 5
minute idle timer circuit is latched on through the
switch. The amber “5 Minute Idle Timer” lamp in the
overhead display will illuminate. The engine will then
shut down after the 5 minute period.
However, if during the 5 minute idle timing sequence,
the 5 minute delay switch (on the instrument panel) is
pressed to the OFF position, the console shutdown
switch is depressed, or the Ground Level Shutdown
switch is activated, the engine will shut down immedi-
ately, followed by the normal shutdown of all sys-
tems.