trailer Ram 3500 Chassis Cab 2018 Service Manual

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 illustrations.
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 after clear from water area.
Four-Pin Connector
1 — Female Pins 4 — Park
2 — Male Pin 5 — Left Stop/Turn
3 — Ground 6 — Right Stop/Turn
304 STARTING AND OPERATING

Towing Tips
Before setting out on a trip, practice turning, stopping, and
backing up the trailer in an area located away from heavy
traffic.
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 shift-
ing 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 per-
formance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
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 transmis-
sion fluid and filter(s) as specified for police, taxi, fleet, or
frequent trailer towing. Refer to the “Maintenance Plan”
for the proper maintenance intervals.
Seven-Pin Connector
1 — Battery 5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes
6
STARTING AND OPERATING 305

NOTE:Check the automatic transmission fluid level be-
fore towing.
Tow/Haul Mode
To reduce potential for automatic transmission overheat-
ing, 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 experience 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 overheat-
ing, take the following actions:
City Driving
In city traffic — while stopped, place the transmission in
NEUTRAL, but do not increase engine idle speed. Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
Air Suspension System
To aid in attaching/detaching the trailer from the vehicle,
the air suspension system can be used. Refer to “Air
Suspension System” in “Starting And Operating” for fur-
ther information.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper leveling of the
air suspension system.
SNOWPLOW
2500/3500 Models Only
Snowplow Prep Packages are available as a factory in-
stalled option. These packages include components neces-
sary to equip your vehicle with a snowplow.
306 STARTING AND OPERATING

RECREATIONAL TOWING (BEHIND MOTORHOME, ETC.)
Towing This Vehicle Behind Another Vehicle
Towing Condition Wheels OFFThe GroundTwo-Wheel
Drive Models Four-Wheel Drive Models
Flat Tow NONE NOT AL-
LOWED See Instructions
•
Automatic transmission in PARK
• Manual transmission in gear (NOT in NEU-
TRAL)
• Transfer case in NEUTRAL (N)
• Tow in forward direction
Dolly Tow FrontNOT AL-
LOWED NOT ALLOWED
Rear OK NOT ALLOWED
On Trailer ALLOK OK
NOTE:
• When towing your vehicle, always follow applicable
state and provincial laws. Contact state and provincial
Highway Safety offices for additional details.
6
STARTING AND OPERATING 309

Recreational Towing — Two-Wheel Drive Models
DO NOT flat tow this vehicle. Damage to the drivetrain
will result.
Recreational towing (for two-wheel drive models) is al-
lowedONLY if the rear wheels are OFFthe ground. This
may be accomplished using a tow dolly or vehicle trailer. If
using a tow dolly, follow this procedure:
1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer’s instructions.
2. Drive the rear wheels onto the tow dolly.
3. Firmly apply the parking brake. Place automatic trans- mission in PARK, manual transmission in gear (not in
NEUTRAL).
4. Properly secure the rear wheels to the dolly, following the dolly manufacturer’s instructions.
5. Turn the ignition OFF and remove the key fob.
6. Install a suitable clamping device, designed for towing, to secure the front wheels in the straight position.
CAUTION!
•Towing with the rear wheels on the ground will
cause severe transmission damage. Damage from
improper towing is not covered under the New
Vehicle Limited Warranty.
• Do not disconnect the driveshaft because fluid may
leak from the transmission, causing damage to inter-
nal parts.
Recreational Towing — Four-Wheel Drive Models
NOTE: Both the manual shift and electronic shift transfer
cases must be shifted into NEUTRAL (N) for recreational
towing. Automatic transmissions must be shifted into
PARK for recreational towing. Manual transmissions must
be placed in gear (NOT in NEUTRAL) for recreational
towing. Refer to the following for the proper transfer case
NEUTRAL (N) shifting procedure for your vehicle.
CAUTION!
• DO NOT dolly tow any 4WD vehicle. Towing with
only one set of wheels on the ground (front or rear)
will cause severe transmission and/or transfer case
(Continued)
310 STARTING AND OPERATING

CAUTION!(Continued)
damage. Tow with all four wheels either ON the
ground, or OFF the ground (using a vehicle trailer).
• Tow only in the forward direction. Towing this
vehicle backwards can cause severe damage to the
transfer case.
• Before recreational towing, the transfer case must be
in NEUTRAL. To be certain the transfer case is fully
in NEUTRAL, perform the procedure outlined under
“Shifting Into NEUTRAL”. Internal transmission
damage will result, if the transfer case is not in
NEUTRAL during towing.
• Automatic transmissions must be placed in PARK,
and manual transmissions must be placed in gear
(not in Neutral) for recreational towing.
• Towing this vehicle in violation of the above require-
ments can cause severe transmission and/or transfer
case damage. Damage from improper towing is not
covered under the New Vehicle Limited Warranty.
• Do not disconnect the rear driveshaft because fluid
will leak from the transfer case, causing damage to
internal parts.
• Do not use a bumper-mounted clamp-on tow bar on
your vehicle. The bumper face bar will be damaged.
Shifting Into NEUTRAL (N)
Use the following procedure to prepare your vehicle for
recreational towing.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the NEU-
TRAL (N) position without first fully engaging the
parking brake. The transfer case NEUTRAL (N) posi-
tion disengages both the front and rear driveshafts
from the powertrain, and will allow the vehicle to roll,
even if the automatic transmission is in PARK (or
manual transmission is in gear). The parking brake
should always be applied when the driver is not in the
vehicle.
CAUTION!
It is necessary to follow these steps to be certain that
the transfer case is fully in NEUTRAL (N) before
recreational towing to prevent damage to internal
parts.
6
STARTING AND OPERATING 311

CavityCartridge Fuse Micro Fuse Description
F08 20 Amp Blue (1500
LD/Cummins Die- sel) –
Emissions Diesel – If Equipped
F09 40 Amp Green (Spe-
cial Services Vehicle& Cummins Diesel) –
Diesel Fuel Heater – If Equipped
F10 40 Amp Green –Body Controller / Exterior Lighting #2
F10 50 Amp Red –Body Controller / Exterior Lighting #2 – If
Equipped with Stop/Start
F11 30 Amp Pink –Integrated Trailer Brake Module – If
Equipped
F12 40 Amp Green –Body Controller #3 / Power Locks
F13 40 Amp Green –Blower Motor
F14 40 Amp Green –Body Controller #4 / Interior Lighting
F16 30 Amp Pink –Smart Bar – If Equipped
F19 20 Amp Blue (1500
LD Diesel)
30 Amp Pink (Cum- mins Diesel) –
SCR – If Equipped
F20 30 Amp Pink –Passenger Door Module
F21 30 Amp Pink –Drive Train Control Module
7
IN CASE OF EMERGENCY 331

CavityCartridge Fuse Micro Fuse Description
F22 20 Amp Blue
30 Amp Pink (Cum- mins Diesel) –
Engine Control Module
F23 30 Amp Pink –Body Controller #1 / Interior Lighting
F24 30 Amp Pink –Driver Door Module
F25 30 Amp Pink – Front Wiper
F26 30 Amp Pink –Antilock Brakes / Stability Control Module /
Valves
F28 20 Amp Blue –Trailer Tow Backup Lights – If Equipped
F29 20 Amp Blue –Trailer Tow Parking Lights – If Equipped
F30 30 Amp Pink –Trailer Tow Receptacle
F31 30 Amp Pink (1500
LD Diesel) –
Urea Heater Control – If Equipped
F32 –– Spare Fuse
F33 20 Amp Blue –Special Services Vehicle Only
F34 30 Amp Pink –Vehicle System Interface Module #2 – If
Equipped
F35 30 Amp Pink –Sunroof – If Equipped
F36 30 Amp Pink –Rear Defroster – If Equipped
F37 30 Amp Pink –Cummins Diesel Fuel Heater #2 – If
Equipped
332 IN CASE OF EMERGENCY

CavityCartridge Fuse Micro Fuse Description
F38 30 Amp Pink –Power Inverter 115V AC – If Equipped
F39 20 Amp Blue –Power Outlet – Special Services Only
F41 –10 Amp Red Active Grill Shutter – If Equipped
F42 –20 Amp Yellow Horn
F44 –10 Amp Red Diagnostic Port
F46 –10 Amp Red Upfitter – If Equipped
F49 –10 Amp Red Instrument Panel Cluster (Except Fleet Ve-
hicles)
F50 –20 Amp Yellow Air Suspension Control Module – If
Equipped
F51 –10 Amp Red Ignition Node Module / Keyless Ignition
(Instrument Panel Cluster – Fleet VehiclesOnly)
F52 –5 Amp Tan Battery Sensor
F53 –20 Amp Yellow Trailer Tow – Left Turn/Stop Lights
F54 –20 Amp Yellow Adjustable Pedals
F56 –15 Amp Blue Additional Diesel Content – If Equipped
F57 –20 Amp Yellow Transmission
F58 –20 Amp Yellow Spare Fuse
F59 –10 Amp Red SCR Relay – If Equipped
7
IN CASE OF EMERGENCY 333

CavityCartridge Fuse Micro Fuse Description
F74 –20 Amp Yellow (Gas
Engine & 1500 LD Diesel) Brake Vacuum Pump Gas/Diesel – If
Equipped
F75 –10 Amp Red Coolant Temperature Valve Actuator
F76 –10 Amp Red Antilock Brakes / Electronic Stability Control
F77 –10 Amp Red Drivetrain Control Module/Front Axle Dis-
connect Module
F78 –10 Amp Red Engine Control Module / Electric Power
Steering
F79 –15 Amp Blue Clearance Lights
F80 –10 Amp Red Universal Garage Door Opener / Compass
F81 –20 Amp Yellow Trailer Tow Right Turn / Stop Lights
F82 –10 Amp Red Steering Column Control Module / Cruise
Control
F84 –15 Amp Blue Switch Bank / Instrument Cluster
F85 –10 Amp Red Airbag Module
F86 –10 Amp Red Airbag Module
F87 –10 Amp Red Air Suspension – If Equipped / Trailer Tow
/ Steering Column Control Module
F88 –15 Amp Blue Instrument Panel Cluster
7
IN CASE OF EMERGENCY 335