Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 124

As the heater uses the heat from
the engine coolant, its heating effect
is weak when the engine coolant
temperature is low.
Maximum Heating : Turn the outlet
6
selector knob to the position, set
the air selector lever to the
position, and turn the temperature
control knob fully towards the high
temperature direction.
Set the fan speed control knob to
the maximum speed position.
Bi-Level Heating : Set the outlet
)
selector knob to the position. Set
the air selector lever to the
position. Set the temperature control
knob to the middle position.
Adjust the fan speed control knob
as desired. The air from the floor
outlets is warmer than the air from
the upper outlets in this position.
However, when the temperature
control knob is moved to either the
full hot or the full cold position, the
air from the floor outlets and the air
from the upper outlets will be the
same temperature. This position can
give cool upper level air and warm
floor level air when the temperature
control is adjusted in between cold
and hot. This is useful in cool
weather with bright sunlight
conditions.
Defogging and Defrosting the
Windshield
Defogging : Set the outlet selector
1
knob to the position. Set the air
selector lever to the position.
Turn the temperature control knob
to a high-temperature position
according to your preference. For
defogging in the summer months,
set the temperature control knob to
any desired position.
Set the fan speed control knob to
any speed position, except the off
position. The A/C compressor
automatically operates when the
position is selected. Defogging is
performed very effectively with the
dehumidifying effect.
Climate Controls
Defrosting : Set the outlet selector
1
knob to the position. Set the air
selector lever to the
Turn the temperature control knob
fully towards the high-temperature
direction. Set the fan speed control
knob to the maximum speed
position.
After defrosting, be certain to return
the air selector lever to the
position. Failure to do so will cause
the windshield to fog up, impeding
forward visibility.
Cooling
Normal/Moderate Cooling : This
setting is suitable for extended
periods of cooling or moderate
cooling. Press the A/C switch to the
on position.
Set the outlet selector knob to the
H
position for normal cooling or set
1
)
it to the position for moderate
cooling. Adjust the temperature
control knob to the desired position.
Adjust the fan speed control knob
as desired
123
position.