Komatsu GD555-5 Operation & Maintenance Manual page 101

EXPLANATION OF COMPONENTS
Conditions for switching fan rotation
Switching from normal rotation to reverse rotation
The fan will switch from normal rotation to reverse rotation only if all the following conditions are fulfilled.
If the direction is switched, the cooling fan reverse rotation pilot lamp on the machine monitor will change from
flashing and will stay lighted up.
If all the conditions are not fulfilled, the fan direction will not change.
If the direction is not switched, the cooling fan reverse rotation pilot lamp on the machine monitor will continue to
flash.
Conditions
Position (A) of the cooling fan reverse rotation switch is pressed once.
The engine speed is between low idle speed and 1200 rpm.
The engine coolant temperature is less than 90°C (The indicator of the engine coolant temperature gauge is at
scale of 8th or less of the bar graph).
The torque converter oil temperature is less than 100°C (The display of the torque converter oil temperature
gauge is within the green range).
At least 30 seconds passed after the engine started.
The gear shift lever is placed in P (PARKING) position.
Switching from reverse rotation to normal rotation
The fan will switch from reverse rotation to normal rotation if any of the following conditions are fulfilled.
If the direction is switched, the cooling fan reverse rotation pilot lamp on the machine monitor will change as follows:
Lighted up -> flashing -> OFF.
If none of the conditions are fulfilled, the fan direction will not change.
If the direction is not switched, the cooling fan reverse rotation pilot lamp on the machine monitor will change from
being lighted up to flashing and will continue to flash.
Conditions
The engine speed becomes less than 1200 rpm in 10 minutes after the fan starts to rotate in reverse.
When pressing the position (A) of the cooling fan reverse rotation switch again during reverse rotation of the fan,
the engine speed becomes less than 1200 rpm.
ROOM LAMP SWITCH
This switch (21) is used to light up the room lamp.
Position (A): OFF
Position (B): Lights up when cab door is opened
Position (C): ON
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OPERATION