2008 DODGE RAM 5500 CHASSIS CAB coolant temperature

INSTRUMENT CLUSTER DESCRIPTION
1. Check Gages
This light illuminates when the Voltmeter, Engine
Oil Pressure or Engine Coolant Temperature
gages indicate a reading either too high or too low.
Examine the gages carefully, and follow the instructions
contained below for each indicated problem.
NOTE:When the ignition switch is turned to OFF, the
Fuel Gage, Voltmeter, Oil Pressure and Engine Coolant
Temperature gages may not show accurate readings.
When the engine is not running, turn the ignition switch
to ON to obtain accurate readings.
2. Voltmeter
When the engine is running, the gauge indicates
the electrical system voltage. The pointer should
stay within the normal range if the battery is charged. Ifthe pointer moves to either extreme left or right and
remains there during normal driving, the electrical sys-
tem should be serviced.
NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gagesº indicator will illuminate
and a single chime will sound.
NOTE:
²The voltmeter may show a gauge fluctuation at vari-
ous engine temperatures. This cycling operation is
caused by the post-heat cycle of the intake manifold
heater system. The number of cycles and the length of
the cycling operation is controlled by the engine
control module. Post-heat operation can run for sev-
eral minutes, and then the electrical system and volt-
meter needle will stabilize.
²The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a noticeable
reduction in blower motor speed.
174 UNDERSTANDING YOUR INSTRUMENT PANEL

9. Oil Pressure Gauge
The pointer should always indicate some oil pres-
sure when the engine is running. A continuous
high or low reading, under normal driving conditions,
may indicate a lubrication system malfunction. Immedi-
ate service should be obtained.(See page 406 for more
information.)
NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gagesº indicator will illuminate
and a single chime will sound.
10. Transfer Case Position
(See page 289 for more information.)
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.(See page 277 for
more information.)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.(See page 277 for more
information.)
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 ª245ÉFº mark, stop the
vehicle, shift into N (Neutral), and increase the engine
idle speed for 2 to 3 minutes. If the temperature reading
does not return to normal, shut your engine OFF and
allow it to cool. Seek authorized service immediately. See
Cooling System information in the section on ªMaintain-
ing Your Vehicle.º
176 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 Gagesº indicator will illuminate
and a single chime will sound.
14. Security Light
The light will flash rapidly for approximately 16 seconds
when the vehicle theft alarm is arming. The light willflash at a slower rate after the alarm is set. The security
light will also come on for about two 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.
UNDERSTANDING YOUR INSTRUMENT PANEL 177
4

the electric shift 4WD system. If the SERV 4WD light
stays on or comes on during driving, it means that the
4WD system is not functioning properly and that service
is required.
23. Water In Fuel Indicator Ð Diesel Only
Indicates there is water detected in the fuel
filter. Refer to the Maintenance section, Drain-
ing Fuel/Water Separator Filter, for water
drain procedure.(See page 417 for more infor-
mation.)
24. Transmission Oil Temperature Warning Light
(Automatic Transmissions Only)
This light indicates that there is excessive trans-
mission fluid temperature that might occur
with severe usage such as trailer towing. It may
also occur when operating the vehicle in a high
torque converter slip condition, such as 4-wheel-drive
operation (e.g. snow plowing, off- road operation). If thislight comes on, stop the vehicle and run the engine at idle
or faster, with the transmission in NEUTRAL until the
light goes off.
25. Wait To Start Indicator Ð Diesel Only
The Wait To Start Indicator will illuminate when
the ignition is turned to the run position and the
intake manifold temperature is below 66 degrees F.
Follow engine starting procedure for proper engine start-
ing and operating. Wait until the Wait To Start Indicator
turns OFF then start the vehicle.
NOTE:The Wait To Start Indicator may not illuminate if
the engine coolant temperature is warm enough.
26. Odometer/Trip Odometer Button
Press this button to toggle between the odometer and the
trip odometer display. Holding the button in resets the
trip odometer reading when in trip mode.
182 UNDERSTANDING YOUR INSTRUMENT PANEL

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.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.
UNDERSTANDING YOUR INSTRUMENT PANEL 245
4

²Allow the engine to idle about three minutes until
the manifold heaters have completed the post-heat
cycle.
²Release the parking brake and drive.
NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
NOTE:If the engine stalls or if the ignition switch is left
On for more than 2 minutes after the WAIT TO START
light goes out, reset the grid heaters by turning the
ignition switch to Off for at least 5 seconds and then back
On. Repeat steps 3 through 7 of the normal starting
procedure.
For Extremely Cold Weather Starting Ð Engine
Manifold Air Temperature Below 0ÉF (- 18ÉC)
In extremely cold weather below 0ÉF (- 18ÉC) it may be
beneficial to cycle the manifold heaters twice before
attempting to start the engine. This can be accomplished
by turning the ignition OFF for at least 5 seconds and
then back ON after the WAIT TO START light has gone
off, but before the engine is started. However, repeated
cycling of the manifold heaters will result in damage to
the heater elements or reduced battery voltage.
NOTE: If multiple pre-heat cycles are used before
starting, additional engine run time may be required to
maintain battery state of charge at a satisfactory level.
²If the engine stalls after the initial start, the ignition
must be turned to the OFF position for at least 5
seconds and then to the ON position to recycle the
manifold heaters.
STARTING AND OPERATING 259
5

NOTE:Excessive white smoke and poor engine perfor-
mance will result if manifold heaters are not recycled.
²Heat generated by the manifold heaters dissipates
rapidly in a cold engine. If more than two minutes
pass between the time the WAIT TO START light goes
OFF and the engine is started, recycle the manifold
heaters by turning the ignition OFF for at least 5
seconds and then back ON.
²If the vehicle is driven and vehicle speed exceeds 19
mph (31 km) before the manifold heater post-heat
(after start) cycle is complete, the manifold heaters will
shut off.
²If the engine is started before the WAIT TO START
light turns off, the preheat cycle will turn off.
²If the engine is cranked for more than 10 seconds, the
post-heat cycle will turn off.NOTE:Engine idle speed will automatically increase to
1000 rpm at low coolant temperatures to improve engine
warm-up.
NOTE:When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air is pulled into
the fuel system.
You may try priming as described below.
1. Add a substantial quantity of fuel to the tank (5 to 10
gallons) or eliminate the gelled fuel condition.
2. Crank the engine for 1 to 2 seconds. If the engine does
not start, then release the key or starter button back to the
RUN position (do not turn the key back to the OFF
position). The electric fuel transfer pump will continue to
run and purge air from the system for about 20 seconds.
After 20 seconds, attempt to start the engine again.
3. Start the engine using the Normal Starting Procedure.
260 STARTING AND OPERATING

Engine Block Heater
The engine block heater warms engine coolant and
permits quicker starts in cold weather. Connect the heater
cord to a ground±fault interrupter protected 110±115 volt
AC electrical outlet with a grounded, three-wire exten-
sion cord.
The engine block heater cord is routed under the hood to
the right side and can be located just behind the grille
near the headlamp.
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 Mopartdealer.
The block heater must be plugged in at least one hour to
have an adequate warming effect on the coolant.WARNING!
Remember to disconnect the cord before driving.
Damage to the 110±115 volt electrical cord could
cause electrocution.
NOTE:The block heater will require 110 Volts AC and
6.5 Amps to activate the heater element.
Block Heater Usage
A.Temperatures below 0ÉF (-18ÉC)
²Block Heater Required for 15W-40
²Block Heater Recommended for 5W-40
B.Temperatures below - 20ÉF (-29ÉC)
²Block Heater Required for 5W-40
264 STARTING AND OPERATING