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Dual Zone Temperature Control
Use this control to regulate the temperature of the air
inside the passenger compartment. This is accomplished
by having separate temperature control slides for both the driver and front passenger. The blue area of the scale
indicates cooler temperatures while the red area indicates
warmer temperatures.
Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use.
NOTE:
When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the air
Dual Zone Temperature Control
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conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
Rear Air Duct—Mega Cab Only
The rear seat will receive air flow in all modes except for
Defrost. The rear air duct is designed to be pointed up when in
A/C mode, and pointed down in Heat mode.
Operating Tips
Fast Cooldown
For a fast cooldown, turn the blower fan rotary knob to
the extreme right position, turn the mode control to the
panel fresh position, press the snowflake button to turn
on the air conditioning, and drive with the windows
open for the first few minutes. Once the hot air has been
expelled, close the windows and press the Recirculation
push-button. When a comfortable condition has been
reached, choose a mode position and adjust the tempera-
ture control slide and blower speed as necessary to
maintain comfort. For high humidity conditions it may
be necessary to remain in the Recirculation mode to
maintain comfort.
Mega Cab Rear Air Duct
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Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it’s rainy or humid. In most cases
turning on the Air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield by using MIX Mode
position on the control. Adjust the temperature control
and blower speed to maintain comfort. Higher blower
speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.
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NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
246 UNDERSTANDING YOUR INSTRUMENT PANEL
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Operating Tips Chart
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The Cummins Diesel engine is equipped with several
features designed to assist cold weather starting and
operation:
•The engine block heater is a resistance heater installed
in the water jacket of the engine just above and behind
the oil filter. It requires a 110–115 volt AC electrical
outlet with a grounded, three-wire extension cord.
NOTE: The engine block heater cord is a factory in-
stalled option. If your vehicle is not equipped, heater
cords are available from your authorized Mopar dealer.
•A 12–volt heater built into the fuel filter housing aids
in preventing fuel gelling. It is controlled by a built-in
thermostat.
•A heated intake air system both improves engine
starting and reduces the amount of white smoke
generated by a warming engine.
Normal Starting Procedure — Engine Manifold
AirTemperature Above 66°F (19°C)
Observe the Instrument Panel Cluster lights when start-
ing the engine.
1. Always apply the parking brake.
2. Shift into PARK for an automatic transmission. Fully
depress and hold the clutch and shift into NEUTRAL for
a manual transmission. Models with manual transmis-
sion are equipped with a clutch interlocking cranking
system. The clutch must be fully depressed to start the
vehicle.
3. Turn the ignition key to the ON position and look at
the instrument panel cluster lamps.
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CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage.
Do Not Operate The Engine With Failed Parts
Practically all failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:
•engine misfiring or vibrating severely
•sudden loss of power
•unusual engine noises
•fuel, oil or coolant leaks
•sudden change, outside the normal operating range, in
the engine operating temperature
•excessive smoke
•oil pressure drop
TRANSMISSION SHIFTING
Automatic Transmission with Overdrive— If
Equipped
The gear shift selector display, located in the instrument
panel cluster, indicates the transmission gear range (the
selector is illuminated for night driving). The selector
lever is mounted on the right side of the steering column.
You must depress the brake pedal, to pull the selector
lever out of park (P) position (Brake Interlock System). To
drive, move the selector lever from Park or Neutral to the
desired drive position. Pull the selector lever toward you
when shifting into Reverse, Second, First or Park, or
when shifting out of Park.
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NOTE:Shifting into or out of 4L is possible with the
vehicle completely stopped, however difficulty may oc-
cur due to the mating clutch teeth not being properly
aligned. Several attempts may be required for clutch
teeth alignment and shift completion to occur. The pre-
ferred method is with the vehicle rolling 2 to 3 mph (3 to
5 km/h). Avoid attempting to engage or disengage 4L
with the vehicle moving faster than 2 to 3 mph (3 to 5
km/h).
NOTE: Do not attempt to shift to or from 4L while the
transmission is in gear or clutch is engaged.
Transfer Case Reminder Light
The four-wheel-drive operating light (4WD), located in
the instrument cluster, is used to alert the driver that the
front axle is fully engaged and all four wheels are
driving.
Electronically Shifted Transfer Case Operating
Information/Precautions–If Equipped
This is an electric shift transfer case and is operated by
the 4WD Control Switch (Transfer Case Switch), which is
located on the instrument panel.
Transfer Case Switch
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