2004 DODGE RAM 2500 DIESEL air conditioning

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
conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
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
pushbutton. When a comfortable condition has beenreached, 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.
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
196 UNDERSTANDING YOUR INSTRUMENT PANEL

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 isencountered, 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 197
4

²Highway Driving Ð
reduce your speed.
²Up Steep Hills Ð
select a lower transmission gear, but try and keep the
torque converter locked.
²Air Conditioning Ð
turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM............... 10psi(69kPa)
Full speed and load.............. 30psi(207 kPa)
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:
²engine misfiring or vibrating severely
²sudden loss of power
²unusual engine noises
²fuel, oil or coolant leaks
STARTING AND OPERATING 217
5

²Highway DrivingÐreduce your speed.
²Air ConditioningÐturn it off temporarily.
²Hilly TerrainÐTurn overdrive off.
See Cooling System Operating information in the Service
and Maintenance section of this manual for more infor-
mation.
Automatic Transmission Oil Temperature Warning
Light
All vehicles with heavy duty transmission oil cooling are
equipped with a transmission sump oil temperature
sensor and warning light. If elevated transmission tem-
peratures are encountered, the engine controller will
select the most desirable gear until the transmission
temperatures are reduced. If transmission oil tempera-
tures continue to rise, a warning light located in theinstrument cluster will illuminate. If this should occur,
stop the vehicle, shift to Neutral, and run the engine at
idle or faster until the light goes off.
Towing With An Automatic Transmission
Vehicles equipped with an automatic transmission may
shift into and out of Overdrive, or a lower gear, when
driving in hilly areas, when heavily loaded, or when
towing into heavy winds.
When this condition occurs, press the ªTOW/HAULº
button or shift into a lower gear to prevent excessive
transmission wear and/or overheating, and to provide
better engine braking.
NOTE:Do not exceed the following RPM while manu-
ally downshifting:
²5.9L Diesel Engines 3200 RPM.
STARTING AND OPERATING 281
5

Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0ÉF (-18É). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized Mopartdealer.
Air Conditioner Maintenance
For best possible performance, your air conditioner
should be checked and serviced by an Authorized Dealer
at the start of each warm season. This service should
include cleaning of the condenser fins and a performance
test. Drive belt tension should also be checked at this
time.
WARNING!
²Use only refrigerants and compressor lubricants
approved by the manufacturer for your air condi-
tioning system. Some unapproved refrigerants are
flammable and can explode, injuring you. Other
unapproved refrigerants or lubricants can cause
the system to fail, requiring costly repairs.
²The air conditioning system contains refrigerant
under high pressure. To avoid risk of personal
injury or damage to the system, adding refrigerant
or any repair requiring lines to be disconnected
should be done by an experienced repairman.
338 MAINTAINING YOUR VEHICLE

Refrigerant Recovery and Recycling
R-134a Air Conditioning Refrigerant is a hydrofluorocar-
bon (HFC) that is endorsed by the Environmental Pro-
tection Agency and is an ozone-saving product. How-
ever, the manufacturer recommends that air conditioning
service be performed by dealers or other service facilities
using recovery and recycling equipment.
NOTE:Air Conditioning systems found to be contami-
nated with A/C System Sealers, Stop Leak Products, Seal
Conditioners, Compressor Oil, or Refrigerants not ap-
proved by the manufacturer, voids the warranty for the
Air Conditioning system.
Power Steering Ð Fluid Check
Checking the power steering fluid level at a defined
service interval is not required. The fluid should only be
checked if a leak is suspected, abnormal noises areapparent, and/or the system is not functioning as antici-
pated. Coordinate inspection efforts through a certified
DaimlerChrysler Dealership.9
WARNING!
Fluid level should be checked on a level surface and
with the engine off to prevent injury from moving
parts and to insure accurate fluid level reading. Do
not overfill. Use only manufacturers recommended
power steering fluid.
If necessary, add fluid to restore to the proper indicated
level. With a clean cloth, wipe any spilled fluid from all
surfaces. Refer to Recommended Fluids, Lubricants, and
Genuine Parts for correct fluid type.
MAINTAINING YOUR VEHICLE 339
7

Air Cleaner, Engine...................331,358
Air Conditioner Maintenance............... 338
Air Conditioning Refrigerant.............338,339
Air Conditioning System................187,338
Air Conditioning System, Zone Control........ 191
Air Filter.............................. 331
Air Pressure, Tires....................252,259
Airbag..............................45,50
Airbag Light.........................70,144
Airbag On/Off Switch..................... 50
Airbag, Side............................ 53
Alarm..............................29,147
Alignment and Balance................... 258
Alterations/Modifications, Vehicle............. 7
Antifreeze (Engine Coolant)................ 345
Capacities........................... 379
Anti-Lock Warning Light...............146,242
Anti-Theft System.....................29,147
Appearance Care........................ 362Ashtray............................... 127
Automatic Transmission................... 353
Adding Fluid......................... 353
Fluid and Filter Changes................. 354
Fluid Level Check...................... 353
Fluid Type........................354,381
Shift Indicator........................ 147
Shifting............................. 218
Special Additives...................... 355
Axle Fluid.......................274,351,381
Axle Lubrication.....................274,351
Ball Joints............................. 340
Battery............................... 336
Blanket..........................213,338
Emergency Starting..................... 310
Bearings.............................. 355
Belts, Drive............................ 331
Belts, Seat.............................. 34
412 INDEX