2020 Ram 4500 Chassis Cab wiring

SAFETY151
Supplemental Restraint Systems (SRS)
Some of the safety features described in this
section may be standard equipment on some
models, or may be optional equipment on
others. If you are not sure, ask an authorized
dealer.
The air bag system must be ready to protect you
in a collision. The Occupant Restraint Controller
(ORC) monitors the internal circuits and inter -
connecting wiring associated with the electrical
Air Bag System Components. Your vehicle may
be equipped with the following Air Bag System
Components:
Air Bag System Components
Occupant Restraint Controller (ORC)
Air Bag Warning Light
Steering Wheel and Column
Instrument Panel
Knee Impact Bolsters
Driver and Front Passenger Air Bags
Seat Belt Buckle Switch
Supplemental Side Air Bags — If Equipped
Front and Side Impact Sensors — If Equipped
Seat Belt Pretensioners — If Equipped
Air Bag Warning Light
The ORC monitors the readiness of
the electronic parts of the air bag
system whenever the ignition switch
is in the START or ON/RUN position. If
the ignition switch is in the OFF position or in the
ACC position, the air bag system is not on and
the air bags will not inflate.
The ORC contains a backup power supply
system that may deploy the air bag system even
if the battery loses power or it becomes discon -
nected prior to deployment.
The ORC turns on the Air Bag Warning Light in
the instrument panel for approximately four to
eight seconds for a self-check when the ignition
switch is first in the ON/RUN position. After the
self-check, the Air Bag Warning Light will turn
off. If the ORC detects a malfunction in any part
of the system, it turns on the Air Bag Warning
Light, either momentarily or continuously. A
single chime will sound to alert you if the light
comes on again after initial startup. The ORC also includes diagnostics that will illu-
minate the instrument panel Air Bag Warning
Light if a malfunction is detected that could
affect the air bag system. The diagnostics also
record the nature of the malfunction. While the
air bag system is designed to be maintenance
free, if any of the following occurs, have an
authorized dealer service the air bag system
immediately.
The Air Bag Warning Light does not come on
during the four to eight seconds when the
ignition switch is first in the ON/RUN position.
The Air Bag Warning Light remains on after
the four to eight-second interval.
The Air Bag Warning Light comes on intermit
-
tently or remains on while driving.
NOTE:
If the speedometer, tachometer, or any engine
related gauges are not working, the Occupant
Restraint Controller (ORC) may also be
disabled. In this condition the air bags may not
be ready to inflate for your protection. Have an
authorized dealer service the air bag system
immediately.
4

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SAFETY157
Air Bag System Components
NOTE:
The Occupant Restraint Controller (ORC) moni -
tors the internal circuits and interconnecting
wiring associated with electrical Air Bag System
Components listed below:
Occupant Restraint Controller (ORC)
Air Bag Warning Light
Steering Wheel and Column
Instrument Panel
Knee Impact Bolsters
Driver and Front Passenger Air Bags
Seat Belt Buckle Switch
Supplemental Side Air Bags — If Equipped
Front and Side Impact Sensors — If Equipped
Seat Belt Pretensioners — If Equipped
If A Deployment Occurs
The front air bags are designed to deflate imme -
diately after deployment. NOTE:
Front and/or side air bags will not deploy in all
collisions. This does not mean something is
wrong with the air bag system.
If you do have a collision which deploys the air
bags, any or all of the following may occur:
The air bag material may sometimes cause
abrasions and/or skin reddening to the occu
-
pants as the air bags deploy and unfold. The
abrasions are similar to friction rope burns or
those you might get sliding along a carpet or
gymnasium floor. They are not caused by
contact with chemicals. They are not perma -
nent and normally heal quickly. However, if
you haven’t healed significantly within a few
days, or if you have any blistering, see your
doctor immediately.
As the air bags deflate, you may see some
smoke-like particles. The particles are a
normal by-product of the process that gener -
ates the non-toxic gas used for air bag infla -
tion. These airborne particles may irritate the
skin, eyes, nose, or throat. If you have skin or
eye irritation, rinse the area with cool water. For nose or throat irritation, move to fresh air.
If the irritation continues, see your doctor. If
these particles settle on your clothing, follow
the garment manufacturer’s instructions for
cleaning.
Do not drive your vehicle after the air bags have
deployed. If you are involved in another colli -
sion, the air bags will not be in place to protect
you.
NOTE:
Air bag covers may not be obvious in the inte -
rior trim, but they will open during air bag
deployment.
After any collision, the vehicle should be
taken to an authorized dealer immediately.
WARNING!
Deployed air bags and seat belt
pretensioners cannot protect you in another
collision. Have the air bags, seat belt
pretensioners, and the seat belt retractor
assemblies replaced by an authorized dealer
immediately. Also, have the Occupant
Restraint Controller System serviced as well.
4

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158SAFETY
(Continued)
Enhanced Accident Response System
In the event of an impact, if the communication
network remains intact, and the power remains
intact, depending on the nature of the event,
the ORC will determine whether to have the
Enhanced Accident Response System perform
the following functions:
Cut off fuel to the engine (If Equipped)
Cut off battery power to the electric motor (If
Equipped)
Flash hazard lights as long as the battery has
power
Turn on the interior lights, which remain on
as long as the battery has power or for
15 minutes from the intervention of the
Enhanced Accident Response System.
Unlock the power door locks.
Your vehicle may also be designed to perform
any of these other functions in response to the
Enhanced Accident Response System:
Turn off the Fuel Filter Heater, Turn off the
HVAC Blower Motor, Close the HVAC Circula -
tion Door
Cut off battery power to the:
Engine
Electric Motor (if equipped)
Electric power steering
Brake booster
Electric park brake
Automatic transmission gear selector
Horn
Front wiper
Headlamp washer pump
NOTE:
After an accident, remember to place the igni -
tion to the STOP (OFF/LOCK) position and
remove the key from the ignition switch to avoid
draining the battery. Carefully check the vehicle
for fuel leaks in the engine compartment and on
the ground near the engine compartment and
fuel tank before resetting the system and
starting the engine. If there are no fuel leaks or
damage to the vehicle electrical devices (e.g.
headlights) after an accident, reset the system
by following the procedure described below. If
you have any doubt, contact an authorized
dealer.
Enhanced Accident Response System Reset
Procedure
In order to reset the Enhanced Accident
Response System functions after an event, the
ignition switch must be changed from ignition
START or ON/RUN to ignition OFF. Carefully
check the vehicle for fuel leaks in the engine
compartment and on the ground near the
engine compartment and fuel tank before reset -
ting the system and starting the engine.
Maintaining Your Air Bag System
WARNING!
Modifications to any part of the air bag
system could cause it to fail when you need
it. You could be injured if the air bag system
is not there to protect you. Do not modify
the components or wiring, including adding
any kind of badges or stickers to the
steering wheel hub trim cover or the upper
passenger side of the instrument panel. Do
not modify the front bumper, vehicle body
structure, or add aftermarket side steps or
running boards.

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STARTING AND OPERATING201
Diesel Particulate Filter (DPF) Manual
Regeneration - If Equipped
On equipped chassis cabs, a manual regenera -
tion can be enable through the instrument
cluster. The manual regeneration will allow the
DPF to complete a regeneration, lowering the
soot level without having to drive the vehicle.
The vehicle must be in park to access this
feature, and the fuel level must be over 12.5%
full. A message displaying the time left on the
regeneration will appear on the instrument
cluster, and the instrument cluster will display
the soot level. Refer to “Instrument Cluster
Display” in “Getting to Know Your Instrument
Panel” for further information.
ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms the engine, and
permits quicker starts in cold weather. Connect
the cord to a standard 110-115 Volt AC elec -
trical outlet with a grounded, three-wire exten -
sion cord.
Gas Engine Only
The engine block heater cord is routed through
the grille by the right front tow hook. It includes a removable cap that is secured by a
tethered strap. It also has a c-clip that is used
for storage when not in use for the Winter
months. During Winter months, remove the
heater cord wiring assembly from itself on the
c-clip.
The engine block heater must be plugged in at
least one hour to have an adequate warming
effect on the engine.
Diesel Engine Only
The engine block heater warms engine coolant
and permits quicker starts in cold weather.
Connect the heater cord to a ground-fault inter
-
rupter protected 110–115 Volt AC electrical
outlet with a grounded, three-wire extension
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
installed option. If your vehicle is not equipped,
heater cords are available from an authorized
Mopar dealer.
The block heater must be plugged in at least
one hour to have an adequate warming effect
on the coolant.
NOTE:
The block heater will require 110 Volts AC and
6.5 Amps to activate the heater element.
Block Heater Usage
For ambient temperatures below 0°F (-18°C),
engine block heater usage is recommended.
For ambient temperatures below –20°F
(-29°C), engine block heater usage is required.
WARNING!
Remember to disconnect the engine block
heater cord before driving. Damage to the
110-115 Volt electrical cord could cause
electrocution.
WARNING!
Remember to disconnect the engine block
heater cord before driving. Damage to the
110-115 Volt electrical cord could cause
electrocution.5

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282STARTING AND OPERATING
The trailer and the vehicle’s stop lamps will
come on when braking normally with the vehicle
brake pedal. Only the trailer stop lamps will
come on when the manual brake control lever is
applied.
Trailer Brake Status Indicator Light
This light indicates the trailer electrical connec -
tion status.
If no electrical connection is detected after the
ignition is turned on, pushing the GAIN adjust -
ment button or sliding the manual brake control
lever will display the GAIN setting for 10
seconds and the “Trailer Brake Status Indicator
Light” will not be displayed.
If a fault is detected in the trailer wiring or the
Integrated Trailer Brake Module (ITBM), the
“Trailer Brake Status Indicator Light” will flash.
GAIN Adjustment Buttons (+/-)
Pushing these buttons will adjust the brake
control power output to the trailer brakes in
0.5 increments. The GAIN setting can be
increased to a maximum of 10 or decreased to
a minimum of 0 (no trailer braking).
GAIN
The GAIN setting is used to set the trailer brake
control for the specific towing condition and
should be changed as towing conditions change. Changes to towing conditions include
trailer load, vehicle load, road conditions and
weather.
Adjusting GAIN
NOTE:
This should only be performed in a traffic free
environment at speeds of approximately
20–25 mph (30–40 km/h).

1. Make sure the trailer brakes are in good
working condition, functioning normally
and properly adjusted. See your trailer
dealer if necessary.

2. Hook up the trailer and make the electrical connections according to the trailer manu -
facturer's instructions.
3. When a trailer with electric/EOH brakes is plugged in, the trailer connected message
should appear in the instrument cluster
display (if the connection is not recognized
by the ITBM, braking functions will not be
available), the GAIN setting will illuminate
and the correct type of trailer must be
selected from the instrument cluster display
options. 4. Push the UP or DOWN button on the
steering wheel until “TRAILER TOW”
appears on the screen.
5. Push the RIGHT arrow on the steering wheel to enter “TRAILER TOW”.
6. Push the UP or DOWN buttons until the Trailer Brake Type appears on the screen.
7. Push the RIGHT arrow and then push the UP or DOWN buttons until the proper Trailer
Brake Type appears on the screen.
8. In a traffic-free environment, tow the trailer on a dry, level surface at a speed of
20–25 mph (30–40 km/h) and squeeze
the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing tires), reduce the GAIN setting; if
the trailer wheels turn freely, increase the
GAIN setting.
Repeat steps 8 and 9 until the GAIN setting is at
a point just below trailer wheel lockup. If towing
a heavier trailer, trailer wheel lockup may not be
attainable even with the maximum GAIN setting
of 10.

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284STARTING AND OPERATING
Towing Requirements — Trailer Lights And
Wiring
Whenever you pull a trailer, regardless of the
trailer size, stoplights and turn signals on the
trailer are required for motoring safety.
The Trailer Tow Package may include a four- and
seven-pin wiring harness. Use a factory
approved trailer harness and connector.
NOTE:
Do not cut or splice wiring into the vehicle’s
wiring harness.
The electrical connections are all complete to
the vehicle but you must mate the harness to a
trailer connector. Refer to the following illustra -
tions.
NOTE:
Disconnect trailer wiring connector from the
vehicle before launching a boat (or any other
device plugged into vehicle’s electrical
connect) into water.
Be sure to reconnect once clear from water
area.
Four-Pin Connector
Seven-Pin Connector

Towing Tips
Before setting out on a trip, practice turning,
stopping, and backing up the trailer in an area
located away from heavy traffic.
1 — Female Pins
2 — Male Pin
3 — Ground
4 — Park
5 — Left Stop/Turn
6 — Right Stop/Turn1 — Battery
2 — Backup Lamps
3 — Right Stop/Turn
4 — Electric Brakes
5 — Ground
6 — Left Stop/Turn
7 — Running Lamps

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302IN CASE OF EMERGENCY
5. Disconnect the internal lamp wiring harness
connector from the low beam bulb.
6. Rotate the bulb counterclockwise a quarter turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers.
High Beam

1. Open the hood.

2. Disconnect and isolate the negative battery cable. 3. Look under the hood and behind the head
-
lamp to find the high beam bulb access
cover.
4. Reach behind the headlamp and disengage the access cover by rotating counterclock -
wise.
5. Disconnect the internal lamp wiring harness connector from the high beam bulb.
6. Rotate the bulb counterclockwise a quarter turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers. Front Park And Turn

1. Open the hood.

2. Disconnect and isolate the negative battery
cable.
3. Look under the hood and behind the head -
lamp to find the park and turn socket.

Park And Turn Socket

4. Reach behind the headlamp and unlock the park and turn socket from the lamp by
rotating counterclockwise a quarter turn.
5. Pull the bulb straight out from the housing.
6. Separate the bulb from the socket without twisting.
7. Reverse the procedure for installation of new bulb and covers.
CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.
Always use the correct bulb size and type
for replacement. An incorrect bulb size or
type may overheat and cause damage to
the lamp, the bulb socket, or the lamp
wiring.
CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.
Always use the correct bulb size and type
for replacement. An incorrect bulb size or
type may overheat and cause damage to
the lamp, the bulb socket, or the lamp
wiring.

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IN CASE OF EMERGENCY303
Side Marker Lamp

1. Open the hood.

2. Disconnect and isolate the negative battery
cable.
3. Reach into the front wheel house ahead of the front wheel, remove the fastener, and
lift the cover over the access hole in the
front of the wheel house splash shield.
Access to the rear of the lamp can be gained
through this access hole.

Splash Shield Access Cover
4. Reach through the access hole of the wheel
house splash shield and disengage the side
marker socket by rotating counterclockwise
a quarter turn.

Side Marker Socket

5. Pull the socket and bulb straight out from the housing.
6. Separate the bulb from the socket without twisting.
7. Reverse the procedure for installation of new bulb and covers.Fog Lamps — If Equipped

1. Reach under and behind the front bumperto access the back of the front fog lamp
housing.

2. Disconnect the fog lamp wiring harness connector from the fog lamp bulb.
3. Rotate the bulb counterclockwise a quarter turn to unlock the bulb from the housing.
4. Pull the bulb straight out from the housing.
1 — Access Cover
2 — Fastener
CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened bulb
life will result.6

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