For proper cold weather operation the heat should be
directed toward the floor level; therefore, close all instrument
panel outlets and fully open driver floor dump outlet. The
driver floor dump is cable operated from a push-pull control at
the instrument panel's upper left-hand side.
Adjust the temperature "HTR" (heat) lever as required
to give the desired degree of heat. The full right "HOT"
position provides the maximum heat. Move the "AIR
OUTLETS" control lever either to the full cab position or to
any of the other three detented positions in order to obtain the
desired air flow distribution between cab heat and defrost
requirements. For the maximum air flow, move the fan switch
to the "HI" position. The heater will also operate with the fan
motor in the "OFF" position due to the ram air introduced
during vehicle operation.
To obtain maximum defrosting, move the "HTR" lever
to the "HOT" position and place the "AIR OUTLETS" lever on
"DEF". Adjust the fan speed to provide the desired air flow.
To clear system of humid air, operate blowers
for 30 seconds at "HI" speed before moving
the "Air Outlets" lever to the "Def" position.
This will minimize rapid fogging of the glass,
which can occur if humid air is blown onto a
REMEMBER a fogging condition limits vision
thru the windshield, which could result in
personal injury or property damage in the
event of an accident.
NEVER drive vehicle unless windshield, rear
surrounding glass area is clear.
To improve defroster efficiency, remove ice
and/or snow from glass area.
FRESH AIR VENTILATION
independent ventilation system or through the heater system
itself. The ventilation system is controlled by rotating the vent
knob located just left of the center instrument panel outlets.
When the knob is turned counterclockwise, air enters the cab
from the hood scoop and flows through the instrument panel
outlets and floor dump. Except for the ventilation mode, the
knob should be rotated to its full clockwise position (vent door
closed) for all other modes of operation.
To increase the quantity of air entering the cab in the
ventilation mode, the fan may be used to power ventilate.
Adjust the fan speed and air outlets for the desired air flow.
To properly air condition your cab in warm weather
close the driver heat dump and open the instrument panel
outlets. Close all windows and ensure the vent knob is turned
to its full clockwise position (vent door closed). Set the "OFF"
position and "A/C" lever on "COLD". For maximum cooling
move the "FAN" switch to the "HI" position. (The fan must be'
on for A/C operation.) Place the "AIR OUTLETS" lever on the
"CAB" position, then adjust the instrument panel outlets to
evenly distribute the air around the occupant's head, chest
and belt areas. If foot areas feel warm, partially open heat
dump to achieve desired comfort.