2008 DODGE RAM 3500 GAS cooling

NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gaugesº indicator will illuminate
and a single chime will sound.
10. Transfer Case Position
This display indicator shows the transfer case position
selection.
For additional information refer to ª4-Wheel Drive Op-
erationº in section 5 of this manual.
11. TOW HAUL
The TOW HAUL button is located at the end of the gear
shift lever. This light will illuminate when the TOW
HAUL OD/OFF button is pushed once.
12. OD/OFF
The OD/OFF button is located at the end of the gear shift
lever. This light will illuminate when the TOW HAUL
OD/OFF button is pushed twice.13. Temperature Gauge
The Temperature Gauge indicates engine coolant
temperature. Any reading within the normal
range indicates that the cooling system is operat-
ing satisfactorily. The gauge needle will likely indicate a
higher temperature when driving in hot weather, up
mountain grades, in heavy traffic, or when towing a
trailer. If the needle rises to the ª245É F (118É C)º mark,
stop the vehicle, shift into NEUTRAL, and increase the
engine idle speed for two to three minutes. If the tem-
perature reading does not return to normal, shut your
engine OFF and allow it to cool. Seek authorized service
immediately. Refer to ªCooling Systemº under ªMain-
taining Your Vehicleº in section 7.
198 UNDERSTANDING YOUR INSTRUMENT PANEL

CAUTION!
Do not leave your vehicle unattended with the en-
gine running as you would not be able to react to the
temperature indicator if the engine overheats.
NOTE:Engine idle speed will automatically increase to
1000 rpm at elevated coolant temperatures to improve
engine cooling.
NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gaugesº indicator will illuminate
and a single chime will sound.
14. Security Light
This light will flash rapidly for approximately 15 seconds
when the Vehicle Security Alarm is arming. The light will
flash at a slower speed continuously after the alarm is set.
The Security light will also come on for about three
seconds when the ignition is first turned on.15. Transmission Range Indicator (Automatic
Transmissions Only)
When the gear selector lever is moved, this indicator
shows the automatic transmission gear range selected.
16. Odometer/Trip Odometer
The odometer shows the total distance the vehicle has
been driven. U.S. federal regulations require that upon
transfer of vehicle ownership, the seller certify to the
purchaser the correct mileage that the vehicle has been
driven. Therefore, if the odometer reading is changed
during repair or replacement, be sure to keep a record of
the reading before and after the service so that the correct
mileage can be determined.
The two trip odometers show individual trip mileage. To
switch from odometer to trip odometers, press and
release the Trip Odometer button.
UNDERSTANDING YOUR INSTRUMENT PANEL 199
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31. CRUISE Light
This indicator lights when the electronic speed control
system is turned on.
32. Coolant Temperature Light ± Base Cluster Only
This light indicates engine coolant temperature is
to high. If the light comes on, stop the vehicle, shift
into NEUTRAL, and increase the engine idle
speed for two to three minutes. If the light does not turn
off, shut your engine OFF and allow it to cool. See an
authorized dealer for service immediately. Refer to
ªCooling Systemº under ªMaintaining Your Vehicleº in
section 7.
CAUTION!
Do not leave your vehicle unattended with the en-
gine running as you would not be able to react to the
temperature indicator if the engine overheats.NOTE:Engine idle speed will automatically increase to
1000 rpm at elevated coolant temperatures to improve
engine cooling.
33. Battery Voltage Indicator Light ± Base Cluster
Only
When the engine is running, this light indicates
the electrical system voltage is out of normal
range. This indicator may also illuminate prior to the
voltage gauge moving out of normal range. In either case,
see you local authorized dealer for system service.
34. Oil Pressure Indicator light ± Base Cluster Only
This light indicates continuous high or low oil
pressure, and under normal driving conditions,
may indicate a lubrication system malfunction. Immedi-
ate service should be obtained.
208 UNDERSTANDING YOUR INSTRUMENT PANEL

Slight changes in engine speed or power may be noticed
when the air conditioning compressor is on. This is a
normal occurrence as the compressor will cycle on and
off to maintain comfort and increase fuel economy.
The mode control (at the right of the
control panel) can be set in any of the
following positions:
NOTE:To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.Recirculation Modes (Panel or Bi-Level)
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel only, or through
both the panel and floor vents depend-
ing on the selected mode (panel vs bi-level).
NOTE:Selecting a Recirculation Mode does not neces-
sarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel.
Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
262 UNDERSTANDING YOUR INSTRUMENT PANEL

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 (cigarettesmoke, 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. For proper coolant type,
refer to ªRecommended Fluids and Genuine Partsº in
Section 7.
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.
UNDERSTANDING YOUR INSTRUMENT PANEL 269
4

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.
270 UNDERSTANDING YOUR INSTRUMENT PANEL

NEUTRAL
Shift to Neutral when the vehicle is standing for pro-
longed periods with the engine running. The engine may
be started in this range. Set the parking brake if you must
leave the vehicle.
DRIVE
This position provides all forward gears, including 3rd
gear direct and 4th or 5th gear overdrive (see Overdrive
Operation). Use this range for most city and highway
driving.
SECOND
Use this position for driving slowly in heavy city traffic
or on mountain roads where more precise speed control
is desirable. Use it also when climbing long grades, and
for engine braking when descending moderately steep
grades. To prevent excessive engine speed do not exceed
45 mph (72 km/h) in this range.FIRST
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in SECOND or FIRST gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth (if equipped) speed
(Overdrive). The transmission will automatically shift
from DRIVE to Overdrive if the following conditions are
present:
²the transmission selector is in DRIVE;
STARTING AND OPERATING 285
5

NOTE:Using the ªTOW HAULº or ªOD/OFFº range
while operating the vehicle under heavy operating con-
ditions will improve performance and extend transmis-
sion life by reducing excessive shifting and heat build up.
This action will also provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAUL OD/OFFº feature ON when
driving in hilly areas or shift the transmission to Drive
position 2 on more severe grades.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
STARTING AND OPERATING 399
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