Heater / Air Conditioner Controls - Komatsu HD1500-7 Operation & Maintenance Manual

OM3238 9/11

HEATER / AIR CONDITIONER CONTROLS

The heater/air conditioner compartment contains
heater/air conditioner controls and some of the
heater/air conditioner components, such as the
blower motor, evaporator and heater coil. Optimum
cab air climate can be obtained by using the
following controls in various combinations.
Fan Speed Control Knob
Fan speed control knob (1, Figure 32-4) controls the
blower motor. The fan (blower) motor is a 3-speed
motor (low, medium and high). Speeds are selected
by rotating the control knob clockwise to the desired
position. OFF is in the full counterclockwise position.
The fan speed control knob must be switched ON for
the air conditioner to function.
Temperature Control Knob
Temperature control knob (2, Figure 32-4) allows the
operator to select a comfortable air temperature.
The control knob determines the operation of the air
conditioning and heater modes.
Rotating the control knob counterclockwise into blue
zone (3) will cause the A/C compressor to operate
and result in cooler air temperatures. The full
counterclockwise position is the coldest air setting.
Rotating the control knob clockwise into red zone (4)
will allow coolant to flow through the heater core
resulting in warmer air temperatures. The full clock-
wise position is the warmest heater setting.
Air Flow Directional Knob
Air flow directional knob (5, Figure 32-4) controls the
direction of airflow as follows:
Provides airflow to floor vents, only.
Provides airflow to upper vents and floor
vents.
(Blue Icon) Provides dehumidified air to
the upper vents and the floor vents.
Defrost - Provides dehumidified air to the
windshield.
Defrost - Provides dehumidified air to the
windshield as well as to floor vents.
Operator Cab and Controls - Section 32
Heater/Air Conditioner Vents
Heater/air conditioner vents (6, Figure 32-4) may be
rotated 360°. There are three vents in the heater/air
conditioner compartment, four vents across the top
of the instrument panel, and one vent each in the RH
and LH instrument panels. There are also an addi-
tional four vents under the instrument panel. Air flow
through the vents is controlled by manually opening,
closing or turning the louvers.
FIGURE 32-4. A/C & HEATER CONTROLS
1. Fan Speed Control
Knob
2. Temperature Control
Knob
3. Blue Zone
Page 32-5
4. Red Zone
5. Air Flow Directional
Knob
6. Vents