Komatsu PC138USLC Operation & Maintenance Manual page 125

DETAILED CONTROLS AND GAUGES
Swing Lock Switch
When not using the swing operation, e.g. when traveling, put the swing lock switch to the OFF position.
On slopes, even when the swing lock switch is at the ON position, the weight of the work equipment may cause the upper
structure to swing if the swing control lever is operated in the downhill direction.
This switch (4) is used to lock the upper structure so that it cannot
swing.
(a) ON position (actuated): The swing lock is always applied, and
(b) OFF position (canceled): The swing lock is released, when
Lamp Switch
This switch (5) is used to light up the working lamp and monitor
lighting.
(a) Night position: Lamps light up and monitor illumination is set to
night mode
(b) Day position: Lamps light up and monitor illumination is set to
day mode
(c) OFF position: Lamps go out.
(The monitor illumination is set to day mode.)
Horn Switch
Use this switch (6) to sound the horn.
Press the switch on the right work control lever to sound the horn.
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the upper structure will not swing even
if the swing is operated. In this
condition, the swing lock lamp lights
up.
operating the swing control lever,
allowing the upper structure to swing.
WARNING
OPERATION