2020 Ram 3500 Chassis Cab air conditioning

52GETTING TO KNOW YOUR VEHICLE
Manual Climate Control Overview

Manual Climate Controls

Icon Description
MAX A/C Setting
Set the Temperature Control Knob to the MAX A/C setting to change the current setting to the coldest output of air. Moving
the temperature control knob away from the MAX A/C setting causes the MAX A/C operation to exit.
A/C Button
Push the A/C button to engage the Air Conditioning (A/C). The A/C indicator illuminates when the A/C is on.
Recirculation Button
Press and release this button on the touchscreen, or push the button on the faceplate, to change the system between
Recirculation mode and outside air mode. The Recirculation indicator and the A/C indicator illuminate when the
Recirculation button is pushed. Recirculation can be used when outside conditions, such as smoke, odors, dust, or
humidity are present. Recirculation can be used in all modes except for Defrost. Recirculation may be unavailable if
conditions exist that could create fogging on the inside of the windshield. The A/C can be deselected manually without
disturbing the mode control selection. Continuous use of the Recirculation mode may make the inside air stuffy and
window fogging may occur. Extended use of this mode is not recommended.

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62GETTING TO KNOW YOUR VEHICLE
Climate Control Functions
A/C (Air Conditioning)
The Air Conditioning (A/C) button allows the
operator to manually activate or deactivate the
air conditioning system. When the air condi -
tioning system is turned on, cool dehumidified
air will flow through the outlets into the cabin.
For improved fuel economy, press the A/C
button to turn off the air conditioning and manu -
ally adjust the blower and airflow mode settings.
Also, make sure to select only Panel, Bi-Level, or
Floor modes.
NOTE:
For Manual Climate Controls, if the system is
in Mix, Floor or Defrost Mode, the A/C can be
turned off, but the A/C system shall remain
active to prevent fogging of the windows.
If fog or mist appears on the windshield or
side glass, select Defrost mode, and increase
blower speed if needed.
If your air conditioning performance seems
lower than expected, check the front of the
A/C condenser (located in front of the radi -
ator), for an accumulation of dirt or insects.
Clean with a gentle water spray from the front
of the radiator and through the condenser. MAX A/C
MAX A/C sets the control for maximum cooling
performance.
Press and release to toggle between MAX A/C
and the prior settings. The button illuminates
when MAX A/C is on.
In MAX A/C, the blower level and mode position
can be adjusted to desired user settings.
Pressing other settings will cause the MAX A/C
operation to switch to the selected setting and
MAX A/C to exit.
Recirculation
In cold weather, use of Recirculation mode may
lead to excessive window fogging. The Recircu
-
lation feature may be unavailable (button on
the touchscreen greyed out) if conditions exist
that could create fogging on the inside of the
windshield.
On systems with Manual Climate Controls, if
equipped, the Recirculation mode is not
allowed in Defrost mode to improve window
clearing operation. Recirculation is disabled
automatically if this mode is selected.
Attempting to use Recirculation while in this
mode causes the LED in the control button to
blink and then turns off.
Automatic Temperature Control (ATC)
Automatic Operation

1. Push the AUTO button on the faceplate, or the AUTO button on the touchscreen on the
Automatic Temperature Control (ATC)
Panel.

2. Next, adjust the temperature you would like the system to maintain by adjusting the
driver and passenger temperature control
buttons. Once the desired temperature is
displayed, the system will achieve and auto -
matically maintain that comfort level.
3. When the system is set up for your comfort level, it is not necessary to change the
settings. You will experience the greatest
efficiency by simply allowing the system to
function automatically.
NOTE:
It is not necessary to move the temperature
settings for cold or hot vehicles. The system
automatically adjusts the temperature,
mode, and blower speed to provide comfort
as quickly as possible.

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GETTING TO KNOW YOUR VEHICLE63
The temperature can be displayed in U.S. or
Metric units by selecting the U.S./Metric
customer-programmable feature. Refer to
the “Uconnect Settings” in “Multimedia” for
further information.
To provide you with maximum comfort in the
Automatic mode during cold start-ups, the
blower fan will remain on low until the engine
warms up. The blower will increase in speed
and transition into Auto mode.
Manual Operation Override
This system offers a full complement of manual
override features. The AUTO symbol in the front
ATC display will be turned off when the system
is being used in the manual mode.
Operating Tips
NOTE:
Refer to the chart at the end of this section for
suggested control settings for various weather
conditions.
Summer Operation
The engine cooling system must be protected
with a high-quality antifreeze coolant to provide
proper corrosion protection and to protect
against engine overheating. OAT coolant
(conforming to MS.90032) is recommended.
Winter Operation
To ensure the best possible heater and
defroster performance, make sure the engine
cooling system is functioning properly and the
proper amount, type, and concentration of
coolant is used. Use of the Air Recirculation
mode during Winter months is not recom -
mended, because it may cause window fogging.
Vacation/Storage
Before you store your vehicle, or keep it out of
service (i.e., vacation) for two weeks or more,
run the air conditioning system at idle for about
five minutes, in fresh air with the blower setting
on high. This will ensure adequate system lubri -
cation to minimize the possibility of compressor
damage when the system is started again.
Window Fogging
Vehicle windows tend to fog on the inside in
mild, rainy, and/or humid weather. To clear the
windows, select Defrost or Mix mode and
increase the front blower speed. Do not use the
Recirculation mode without A/C for long
periods, as fogging may occur.
CAUTION!
Failure to follow these cautions can cause
damage to the heating elements:
Use care when washing the inside of the
rear window. Do not use abrasive window
cleaners on the interior surface of the
window. Use a soft cloth and a mild
washing solution, wiping parallel to the
heating elements. Labels can be peeled off
after soaking with warm water.
Do not use scrapers, sharp instruments, or
abrasive window cleaners on the interior
surface of the window.
Keep all objects a safe distance from the
window.
2

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200STARTING AND OPERATING
Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (anti -
freeze: a mixture of 50% ethylene-glycol and
50% water) must not exceed the normal range
of the temperature gauge 240°F (116°C) with
a 21 psi (145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze)
temperature indicated during operation will be
to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant (anti -
freeze) temperature below the normal range on
the gauge 140°F (60°C) can be harmful to the
engine. Low engine coolant (antifreeze)
temperature can cause incomplete combustion
which allows carbon and varnish to form on
piston rings and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the
engine.
Cooling System Tips
To reduce potential for engine and transmission
overheating in high ambient temperature condi -
tions, take the following actions:
City Driving — When stopped, shift the trans -
mission into NEUTRAL and increase engine
idle speed.
Highway Driving — Reduce your speed.
Up Steep Hills — Select a lower transmission
gear.
Air Conditioning — 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:
Do Not Operate The Engine With Failed Parts
All engine failures give some warning before the
parts fail. Be on the alert for changes in perfor -
mance, 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 oper -
ating range, in the engine operating tempera -
ture.
Excessive smoke.
Oil pressure drop.
Idle 700 to 800 RPM 10 psi (69 kPa)
Full speed and load 30 psi (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.

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STARTING AND OPERATING285
Automatic Transmission
The DRIVE range can be selected when towing.
The transmission controls include a drive
strategy to avoid frequent shifting when towing.
However, if frequent shifting does occur while in
DRIVE, select TOW/HAUL mode or select a lower
gear range (using the Electronic Range Select
(ERS) shift control).
NOTE:
Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while
operating the vehicle under heavy loading
conditions will improve performance and
extend transmission life by reducing excessive
shifting and heat build up. This action will also
provide better engine braking.
Six-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades at
low speeds (20 mph [32 km/h] or below),
holding your vehicle in first gear (using the ERS
shift control) can help to avoid transmission
overheating. If you regularly tow a trailer for more than
45 minutes of continuous operation, then
change the automatic transmission fluid and
filter(s) as specified for "police, taxi, fleet, or
frequent trailer towing." Refer to the “Mainte
-
nance Plan” for the proper maintenance inter -
vals.
NOTE:
Check the automatic transmission fluid level
before towing (Six-speed automatic only).
Tow/Haul Mode
To reduce potential for automatic transmission
overheating, activate TOW/HAUL mode when
driving in hilly areas, or select a lower gear
range (using the Electronic Range Select (ERS)
shift control) on more severe grades.
Speed Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Speed Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Speed Control in flat terrain and with
light loads to maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase
engine idle speed.
Highway Driving
Reduce speed.
Temporarily turn off air conditioning.
5

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310IN CASE OF EMERGENCY
F56 –15 Amp Blue Additional Diesel Content - If Equipped (DS 1500 Only)
F56 –10 Amp Red Fuel Vapor Blocker Valve - If Equipped (HD Only)
F57 –20 Amp Yellow TCM/PCM / Solenoid Trans Pressure SW (RFE Trans Only)
– If Equipped (HD Only)
Transmission (DS 1500 Only)
F58 –10 Amp Red Bed Lighting (LED) – If Equipped (HD Only)
F60 –15 Amp Blue Underhood Lamp / TCM – If Equipped (DS 1500 Only)
F61 –10 Amp RedUREA Sensor / PM Sensor – If Equipped (DS 1500 LD
Diesel & Cummins Diesel)
F62 –10 Amp Red Air Conditioning Clutch
F63 –20 Amp Yellow Ignition Coils (Gas), Ignition Coils Capacitors (Gas) / Short
Runner Valve Actuator / Urea Heater Control Unit (DS
1500 LD Diesel) / RLY Coil Feed-SCR (DS 1500 LD Diesel)
F64 –25 Amp ClearFuel Injectors / Powertrain Control Module / SRV – If
Equipped
F65 –10 Amp RedMOD Inverter (Wake Up) / Power Port / USB IP / WCPM –
If Equipped (HD Only)
Spare (DS 1500 Only)
F66 –10 Amp RedSunroof / Light and Rain Sensor Module / Inside Rearview
Mirror / Passenger Window SW / USB Port Rear / Feed for
R/A RLY #2 Coil – If Equipped
F67 –10 Amp RedCD / DVD / UCI Port – If Equipped (HD Only)
Bluetooth Hands-Free Module / CD – If Equipped (DS
1500 Only)
Cavity
Cartridge Fuse Micro Fuse Description

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SERVICING AND MAINTENANCE351
3. Remove the air cleaner filter element from
the housing assembly.

Air Cleaner Filter

Engine Air Cleaner Filter Installation
NOTE:
Inspect and clean the housing if dirt or debris is
present before replacing the air filter element.

1. Install the air cleaner filter element into the housing assembly with the air cleaner filter
inspection surface facing downward.

2. Install the air cleaner cover onto the housing assembly locating tabs. 3. Install screws to secure the air cleaner
cover to the housing assembly.
Air Conditioner Maintenance
For best possible performance, your air condi -
tioner 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.
Refrigerant Recovery And Recycling R-134a
— If Equipped
R-134a Air Conditioning Refrigerant is a hydro -
fluorocarbon (HFC) that is an ozone-friendly
substance. The manufacturer recommends
that air conditioning service be performed by an
authorized dealer or other service facilities
using recovery and recycling equipment.
NOTE:
Use only manufacturer approved A/C system
PAG compressor oil and refrigerants.
1 — Air Cleaner Filter
2 — Air Cleaner Filter Inspection Surface
WARNING!
Use only refrigerants and compressor lubri -
cants approved by the manufacturer for
your air conditioning system. Some unap -
proved refrigerants are flammable and can
explode, injuring you. Other unapproved
refrigerants or lubricants can cause the
system to fail, requiring costly repairs.
Refer to Warranty Information Book, for
further warranty information.
The air conditioning system contains refrig -
erant 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 technician.
CAUTION!
Do not use chemical flushes in your air
conditioning system as the chemicals can
damage your air conditioning components.
Such damage is not covered by the New
Vehicle Limited Warranty.
7

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352SERVICING AND MAINTENANCE
Refrigerant Recovery And Recycling
R-1234yf — If Equipped
R-1234yf Air Conditioning Refrigerant is a
hydrofluoroolefin (HFO) that is endorsed by the
Environmental Protection Agency and is an
ozone-friendly substance with a low
global-warming potential. The manufacturer
recommends that air conditioning service be
performed by an authorized dealer using
recovery and recycling equipment.
NOTE:
Use only manufacturer approved A/C system
PAG compressor oil, and refrigerants.
Cabin Filter Replacement (A/C Air Filter)
Refer to the “Maintenance Plan” for the proper
maintenance intervals. The cabin air filter is located in the fresh air inlet
behind the glove compartment. Perform the
following procedure to replace the filter:

1. Open the glove compartment and remove
all contents.

2. With the glove compartment door open, remove the glove compartment tension
tether and tether clip by sliding the clip
toward the face of the glove compartment
door. Lift the clip out of glove compartment
door and release into dash panel.

Right Side Of Glove Compartment
3. There are travel stops on both sides of the
glove compartment. Push inward on right
side of the glove compartment travel stop to
disengage the stop. Then pull the right of
the glove compartment outward (away from
the hinge) to disengaging the right side of
the compartment from the hinge. Continue
by removing the left side from the hinge by
slightly lowering the compartment while
pulling outward until it is completely disen -
gaged from the hinge.

Glove Compartment

WARNING!
Do not remove the cabin air filter while the
vehicle is running, or while the ignition is in
the ACC or ON/RUN mode. With the cabin air
filter removed and the blower operating, the
blower can contact hands and may propel dirt
and debris into your eyes, resulting in
personal injury.
1 — Glove Compartment Door
2 — Glove Compartment Tension Tether
1 — Glove Compartment Travel Stop
2 — Glove Compartment Tension Tether
3 — Glove Compartment Door

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