2021 RAM CHASSIS CAB ignition

372SERVICING AND MAINTENANCE
Refrigerant Recovery And Recycling
R-134a — If Equipped
R-134a Air Conditioning Refrigerant is
a hydrofluorocarbon (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.
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 Air Filter Replacement
For the proper maintenance intervals
Úpage 354.
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

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

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374SERVICING AND MAINTENANCE

8. Pull the tension tether outward and reinstall the
glove compartment past the travel stops by
pushing in on the glove compartment sides.

Glove Compartment

NOTE:
Ensure the glove compartment door hinges and
glove compartment travel stops are fully
engaged.
9. Reattach the glove compartment tension tether by inserting the tether clip in the
glove compartment and sliding the clip
away from the face of the glove
compartment door.ACCESSORY DRIVE BELT INSPECTION
When inspecting accessory drive belts, small
cracks that run across ribbed surface of belt
from rib to rib, are considered normal. These
are not a reason to replace belt. However,
cracks running along a rib (not across) are not
normal. Any belt with cracks running along a rib
must be replaced. Also have the belt replaced if
it has excessive wear, frayed cords or severe
glazing.
Accessory Belt (Serpentine Belt)

Conditions that would require replacement:
Rib chunking (one or more ribs has sepa -
rated from belt body)
Rib or belt wear
Longitudinal belt cracking (cracks between
two ribs)
Belt slips
“Groove jumping" (belt does not maintain
correct position on pulley)
Belt broken (note: identify and correct
problem before new belt is installed)
Noise (objectionable squeal, squeak, or
rumble is heard or felt while drive belt is in
operation)
1 — Glove Compartment Travel Stop
2 — Glove Compartment Tension Tether
3 — Glove Compartment Door
WARNING!
Do not attempt to inspect an accessory
drive belt with vehicle running.
When working near the radiator cooling fan,
disconnect the fan motor lead. The fan is
temperature controlled and can start at any
time regardless of ignition mode. You could
be injured by the moving fan blades.

You can be badly injured working on or
around a motor vehicle. Only do service work
for which you have the knowledge and the
proper equipment. If you have any doubt
about your ability to perform a service job,
take your vehicle to a competent mechanic.

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SERVICING AND MAINTENANCE375
Some conditions can be caused by a faulty
component such as a belt pulley. Belt pulleys
should be carefully inspected for damage and
proper alignment.
Belt replacement on some models requires the
use of special tools, we recommend having your
vehicle serviced at an authorized dealer.
DRAINING FUEL/WATER SEPARATOR
F
ILTER
There are two fuel filter assemblies. One is
located on the driver's side of the engine.
The best access to this water drain valve is from
under the hood. The second one is on the under
body, located in front of the rear axle above the
drive shaft on pick-up models. The Chassis Cab
models second filter location is on the frame
behind the front axle. The best access to this
water drain valve is from under the vehicle. If water is detected in the water separator while
the engine is running, or while the ignition
switch is in the ON position, the “Water In Fuel
Indicator Light” will illuminate and an audible
chime will be heard five times. At this point you
should stop the engine and drain the water from
both of the filters.
If the “Water In Fuel Indicator Light” comes on
and a single chime is heard while you are
driving, or with the ignition switch in the ON
position, there may be a problem with your
water separator wiring or sensor. See an
authorized dealer for service.
Upon proper draining of the water from both
fuel filters, the “Water In Fuel Indicator Light”
will remain illuminated for approximately
10 seconds. If the water was drained while
the engine was running, the “Water In Fuel
Indicator Light” may remain on for
approximately three minutes.NOTE:
Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately
discarded, can present a problem to the envi
-
ronment. Contact an authorized dealer, service
station, or government agency for advice on
recycling programs and for where used fluids
and filters can be properly disposed of in your
area.

Drain the fuel/water separator filters when the
“Water In Fuel Indicator Light” is ON. Within
10 minutes of vehicle shutdown, turn the engine
mounted filter drain valve (located on the side of
the filter assembly) counterclockwise a quarter
turn, and turn the under body mounted filter
drain valve (located on the bottom of the filter
assembly) counterclockwise 1 full turn. Then turn
the ignition switch to the ON position, and allow
any accumulated water to drain. Leave the drain
valve open until all water and contaminants have
been removed. When clean fuel is visible, close
the drain valve following these guidelines:

1. Rotate the drain clockwise to close until you feel resistance from the internal seal.

2. Continue turning the drain half of a turn to properly compress the seal.
CAUTION!
Do not drain the fuel/water separator filter
when the engine is running.
Diesel fuel will damage blacktop paving
surfaces. Drain the filter into an appro-
priate container.
CAUTION!
If the “Water In Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain water from the fuel filters to avoid
engine damage.
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376SERVICING AND MAINTENANCE
NOTE:
Over-compression of the seal due to over-tight -
ening of the drain will damage the seal, cause
a leak, and require the entire sensor to be
replaced.
3. Turn the ignition switch to OFF.
The sensor drain should not be over-tightened
during normal service operations to avoid
internal damage and future fuel leaks.
The drain should be closed and secured
without the use of tools.
If more than a couple ounces/milliliters of fuel
have been drained, follow the directions for
“Priming If The Engine Has Run Out Of Fuel”
Ú page 378
ENGINE MOUNTED FUEL FILTER
R
EPLACEMENT
NOTE:
Using a fuel filter that does not meet the
manufacturer's filtration and water sepa -
rating requirements can severely impact fuel
system life and reliability.
The engine mounted filter housing is
equipped with a No-Filter-No-Run (NFNR)
feature. Engine will not run if:
a. No filter is installed.
b. Inferior/Non-approved filter is used. Use of OEM filter is required to ensure
vehicle will run.

Engine Mounted Fuel Filter Assembly
1. Ensure engine is turned off.

2. Place drain pan under the fuel filter drain
hose.
3. Open the water drain valve a quarter turn counterclockwise and completely drain fuel
and water into the approved container.
4. Close the water drain valve.
5. Remove lid using a socket or strap wrench. Rotate counterclockwise for removal.
Remove used o-ring and discard it.
1 — Drain Valve
CAUTION!
Diesel fuel will damage blacktop paving
surfaces. Drain the filter into an appro-
priate container.
Do not prefill the fuel filter when installing a
new fuel filter. There is a possibility debris
could be introduced into the fuel filter
during this action. It is best to install the
filter dry and allow the in-tank lift pump to
prime the fuel system.

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378SERVICING AND MAINTENANCE
7. Wipe clean the sealing surfaces of the lid
and housing.
8. Install new o-ring back into ring groove on the filter housing and lubricate with clean
engine oil.
NOTE:
Water In Fuel (WIF) sensor is re-usable. Service
kit comes with new o-ring for filter canister and
WIF sensor.
PRIMING IF THE ENGINE HAS RUN OUT
O
F FUEL

1. Add a substantial amount of fuel to the
tank, approximately 2 to 5 gal (8L to 19L).
2. Three priming cycles must be completed.
Turn ignition to the RUN position and wait
approximately 30 seconds. This will activate
the in tank fuel pump. Turn the ignition
switch to the off position, and leave off for at
least 30 seconds. Repeat this procedure
three times before cranking the engine.
3. Start the engine using the “Normal Starting” procedure Ú page 119.
4. Once the engine starts, allow the engine to idle for a minimum of 30 seconds.
NOTE:
The engine may run rough until the air is forced
from all the fuel lines. NOTE:
A maximum blend of 5% biodiesel, meeting
ASTM specification D-975 may be used with
your Cummins diesel engine. (Chassis Cab
models not configured with B20 capability.)
A maximum blend of 20% biodiesel, meeting
ASTM specification D-7467 may be used with
your Cummins diesel engine. (Pickup models
and Chassis Cab models configured with B20
capability.)
WARNING!
Do not open the high pressure fuel system
with the engine running. Engine operation
causes high fuel pressure. High pressure fuel
spray can cause serious injury or death.
CAUTION!
Do not engage the starter motor for more
than 15 seconds at a time. Allow two minutes
between the cranking intervals.
WARNING!
Do not use alcohol or gasoline as a fuel
blending agent. They can be unstable under
certain conditions and be hazardous or
explosive when mixed with diesel fuel.
CAUTION!
Due to lack of lubricants in alcohol or
gasoline, the use of these fuels can cause
damage to the fuel system.

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SERVICING AND MAINTENANCE383

Under normal operating conditions, the catalytic
converter will not require maintenance. However,
it is important to keep the engine properly tuned
to ensure proper catalyst operation and prevent
possible catalyst damage.
NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.

In unusual situations involving grossly
malfunctioning engine operation, a scorching
odor may suggest severe and abnormal catalyst
overheating. If this occurs, stop the vehicle, turn off
the engine and allow it to cool. Service, including a
tune-up to manufacturer's specifications, should be
obtained immediately.

To minimize the possibility of catalytic converter
damage:
Do not interrupt the ignition when the trans
-
mission is in gear and the vehicle is in
motion.
Do not try to start the vehicle by pushing or
towing the vehicle.
Do not idle the engine with any ignition
components disconnected or removed, such
as when diagnostic testing, or for prolonged
periods during very rough idle or malfunc -
tioning operating conditions.
COOLING SYSTEM CAUTION!
The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as
an emissions control device and may seri -
ously reduce engine performance and
cause serious damage to the engine.

Damage to the catalytic converter can result
if your vehicle is not kept in proper operating
condition. In the event of engine malfunc -
tion, particularly involving engine misfire or
other apparent loss of performance, have
your vehicle serviced promptly. Continued
operation of your vehicle with a severe
malfunction could cause the converter to
overheat, resulting in possible damage to
the converter and vehicle.

WARNING!

You or others can be badly burned by hot
engine coolant (antifreeze) or steam from your
radiator. If you see or hear steam coming from
under the hood, do not open the hood until the
radiator has had time to cool. Never open a
cooling system pressure cap when the radiator
or coolant bottle is hot.

Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts automati -
cally and may start at any time, whether the
engine is running or not.
When working near the radiator cooling fan,
disconnect the fan motor lead or turn the
ignition to the OFF mode. The fan is
temperature controlled and can start at any
time the ignition is in the ON mode.
8

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394SERVICING AND MAINTENANCE
(Continued)
FUSES
General Information The fuses protect electrical systems against
excessive current.
When a device does not work, you must check
the fuse element inside the blade fuse for a
break/melt.
Also, please be aware that when using power
outlets for extended periods of time with the
engine off may result in vehicle battery
discharge.
Blade Fuses

PERFORMED BY
PERFORMED AT
Noise Systems Maintenance Chart and Service Log — Insert Month, Day, Year under column mileage closest to the mileage at which
service was performed.
WARNING!
When replacing a blown fuse, always use
an appropriate replacement fuse with the
same amp rating as the original fuse. Never
replace a fuse with another fuse of higher
amp rating. Never replace a blown fuse with
metal wires or any other material. Do not
place a fuse inside a circuit breaker cavity
or vice versa. Failure to use proper fuses
may result in serious personal injury, fire
and/or property damage.
Before replacing a fuse, make sure that the
ignition is off and that all the other services
are switched off and/or disengaged.
If the replaced fuse blows again, contact an
authorized dealer.
If a general protection fuse for safety
systems (air bag system, braking system),
power unit systems (engine system, trans
-
mission system) or steering system blows,
contact an authorized dealer.
WARNING! (Continued)
1 — Fuse Element
2 — Blade Fuse with a good/functional fuse
element
3 — Blade fuse with a bad/not functional fuse
element (blown fuse)

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SERVICING AND MAINTENANCE397
F32– –Spare
F33 20 Amp Blue –Trans Control Module – If Equipped
F34 30 Amp Pink –Vehicle System Interface Module #2 – If Equipped
F35 30 Amp Pink –Sunroof – If Equipped
F36 30 Amp Pink –Electric Back Light – If Equipped
F37 30 Amp Pink –Diesel Frame / Fuel Heater #2– If Equipped
F38 30 Amp Pink –Integrated Trailer Brake Module – If Equipped
F39 – –Spare
F40 –10 Amp Red Ventilated Seats – If Equipped
F41 –10 Amp Red Active Grille Shutter / Active Air Dam – If Equipped
F42 –20 Amp Yellow Horn
F43 –15 Amp Blue Heated Steering Wheel – If Equipped
F44 –10 Amp Red Diagnostic Port
F46 –10 Amp Red Upfitters Relay Coil – If Equipped
F47 – –Spare
F48 – –Spare
F49 –10 Amp Red IP Cluster / CSG
F50 –20 Amp Yellow Air Suspension Control Module – If Equipped
F51 –10 Amp RedIgnition Node Module / Keyless Ignition Node Module, Radio Frequency
Hub Module / Electric Steering Column Lock - If Equipped
F52 –5 Amp Tan Battery Sensor
Cavity Cartridge Fuse Micro Fuse Description
8

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