Komatsu GD555-5 Operation & Maintenance Manual page 100

OPERATION
REMARK
To carry out operations with effective fuel consumption, normally set to the E mode.
The maximum engine speed is set lower in E mode than in P mode, but it can display ample power and can also
display good fuel consumption in working or traveling on flat ground.
Set to the P mode if large drawbar pull is required when carrying out operations or traveling on slopes or if high
speeds are required when traveling on flat ground or uphill.
REAR WORKING LAMP SWITCH
This switch (19) is used to light up the rear working lamp.
Position (A): Working lamp lights up
Position (B): OFF
REMARK
The rear working lamp lit only when the front working lamp is lit.
In case the front working lamp is OFF, the rear lamp does not light
up even when the rear working lamp switch is set to the position
(A).
COOLING FAN REVERSE ROTATION SWITCH
Use this switch (20) to rotate the cooling fan in reverse to clean the
radiator.
When operating the switch, run the engine at low idle.
Position (A): Reverse rotation switch ON
When the fan is rotating in the normal direction, if the
switch is pressed once, the fan rotates in reverse; if
the switch is pressed again, the fan rotates in the
normal direction.
When the fan is rotating in the reverse direction, the
cooling fan reverse rotation pilot lamp on the machine
monitor lights up. For procedures of the cleaning, see
the item in "CLEAN RADIATOR FINS AND COOLER
FINS (PAGE 4-31)".
Position (B): OFF (Neutral)
REMARK
The reverse rotation of the fan can be used only when the gear shift lever is in P (PARKING) position.
When the direction of fan rotation switches over, the reverse rotation pilot lamp flashes.
To protect the machine, the direction of fan rotation does not switch over in some cases during high load
operations or in low temperatures. (For details, see the conditions for switching the fan rotation.)
When the engine stops, the fan rotation returns to the normal direction.
When the switch is set to A (REVERSE ROTATION ON) position and the switch is released, it returns to B (OFF
(NEUTRAL)) position. Even if the switch is not pressed continuously at A position, the fan rotates in reverse. Be
sure to release the switch.
When the fan is rotating in reverse, if the engine coolant temperature, hydraulic oil temperature, or torque
converter oil temperature overheats (the caution lamp for the oil temperature gauge on the machine monitor
lights up), the reverse rotation of the fan is forcibly stopped and the fan returns to rotation in the normal direction.
EXPLANATION OF COMPONENTS
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