1998 DODGE RAM 1500 Fig

STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING TUBING
AND FITTINGS
CAUTION: The system must be completely empty
before opening any fitting or connection in the
refrigeration system. Open fittings with caution
even after the system has been emptied. If any
pressure is noticed as a fitting is loosened,
retighten fitting and evacuate the system again.
A good rule for the flexible hose lines is to keep the
radius of all bends at least 10 times the diameter of
the hose. Sharper bends will reduce the flow of
refrigerant. The flexible hose lines should be routed
so they are at least 3 inches (80 mm) from the
exhaust manifold. Inspect all flexible hose lines to
make sure they are in good condition and properly
routed.
The use of correct wrenches when making connec-
tions is very important. Improper wrenches or
improper use of wrenches can damage the fittings.
The internal parts of the A/C system will remain sta-
ble as long as moisture-free refrigerant and refrig-
erant oil is used. Abnormal amounts of dirt,
moisture or air can upset the chemical stability.
This may cause operational troubles or even seri-
ous damage if present in more than very small
quantities. Before disconnecting a component,
clean the outside of the fittings thoroughly to pre-
vent contamination from entering the refrigerant
system.
When opening a refrigeration system, have every-
thing you will need to repair the system ready. This
will minimize the amount of time the system must
be opened. Cap or plug all lines and fittings as
soon as they are opened. This will help prevent the
entrance of dirt and moisture. All new lines and
components should be capped or sealed until they
are ready to be used. Before connecting a compo-
nent, clean the outside of the fittings thoroughly to
prevent contamination from entering the refrigerant
system.
All tools, including the refrigerant dispensing mani-
fold, the manifold gauge set, and test hoses should
be kept clean and dry.
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are pro-
duced in the system when it is operating. Extreme
care must be exercised to make sure that all connec-
tions are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replace-
ment of lines or components. The refrigerant oil willabsorb moisture readily out of the air. This moisture
will convert into acids within a closed system.
STANDARD PROCEDURE - DIODE
REPLACEMENT
(1) Disconnect and isolate the battery negative
cable. If the vehicle has dual batteries, remove the
negative cable from both batteries.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness. Note the
direction of current flow (Fig. 1).
(4) Remove the insulation from the wires in the
harness. Only remove enough insulation to solder in
the new diode.
(5) Install the new diode in the harness, making
sure current flow is correct. If necessary refer to the
appropriate wiring diagram for current flow.
(6) Solder the connections together using rosin
core type solder only.Do not use acid core solder.
(7) Tape the diode to the harness using electrical
tape. Make sure the diode is completely sealed from
the elements.
(8) Reconnect the battery negative cable(s) and
test the affected systems.
Fig. 1 Diode Identification
1 - CURRENT FLOW
2 - BAND INDICATES CURRENT FLOW
3 - DIODE AS SHOWN IN WIRING DIAGRAMS
DRPLUMBING 24 - 45
PLUMBING (Continued)

STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT
WARNING: EYE PROTECTION MUST BE WORN
WHEN SERVICING AN AIR CONDITIONING REFRIG-
ERANT SYSTEM. TURN OFF (ROTATE CLOCKWISE)
ALL VALVES ON THE EQUIPMENT BEING USED
BEFORE CONNECTING TO, OR DISCONNECTING
FROM THE REFRIGERANT SYSTEM. FAILURE TO
OBSERVE THESE WARNINGS MAY RESULT IN PER-
SONAL INJURY.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 must be used
(Fig. 2). Contact an automotive service equipment
supplier for refrigerant recovery/recycling/charging
equipment. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
A manifold gauge set may be needed with some
recovery/recycling/charging equipment (Fig. 3). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
LOW PRESSURE GAUGE HOSE The low pressure
hose (Blue with Black stripe) attaches to the low side
service port. This service port is located on the suc-
tion line between the accumulator outlet port and the
A/C compressor.
HIGH PRESSURE GAUGE HOSE The high pres-
sure hose (Red with Black stripe) attaches to the
high side service port. This service port is located on
the discharge line near the A/C compressor. On this
model, an A/C pressure transducer is installed onto
the high pressure service port. A/C high side pres-
sures can be read using a DRBIIItscan tool. Refer to
Body Diagnostic Procedures.
RECOVERY/RECYCLING/EVACUATION/CHARG-
ING HOSE The center manifold hose (Yellow, or
White, with Black stripe) is used to recover, evacu-
ate, and charge the refrigerant system. When the low
or high pressure valves on the manifold gauge set
are opened, the refrigerant in the system will escape
through this hose.
Fig. 2 Refrigerant Recovery/Recycling Station -
Typical
1 - R-134a REFRIGERANT STATION
Fig. 3 MANIFOLD GAUGE SET - TYPICAL
1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/ BLACK STRIPE)
4 - HIGH PRESSURE HOSE (RED W/ BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/ BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE
24 - 46 PLUMBINGDR
PLUMBING (Continued)

ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Disconnect the A/C compressor clutch coil wire
harness connector.
(5) Depending on engine usage, remove the bolt or
nuts that secure the suction and discharge line fit-
tings to the A/C compressor.
(6) Disconnect the suction and discharge line fit-
tings from the A/C compressor.
(7) Remove the O-ring seals from the suction and
discharge line fittings and discard.
(8) Install plugs in, or tape over all of the opened
refrigerant line fittings and the compressor ports.
(9) If equipped with the 5.7L Hemi engine, remove
the nuts and bolts that secure the generator and A/C
compressor support bracket and remove the bracket
from the engine.
(10) Remove the bolts that secure the A/C com-
pressor to the mounting bracket (Fig. 4), (Fig. 5) or
(Fig. 6).
(11) Remove the A/C compressor from the engine
compartment.
Fig. 4 A/C Compressor - 3.7L Shown, 4.7L Typical
1 - BOLT #1
2 - BOLT #2
3 - BOLT #3
4 - A/C COMPRESSOR
5 - A/C CLUTCH AND PULLEY
6 - MOUNTING BRACKET
Fig. 5 A/C Compressor - 5.7L Hemi
1 - BOLT (2)
2 - A/C COMPRESSOR
3 - BOLT
4 - MOUNTING BRACKET
Fig. 6 A/C Compressor - 5.9L Diesel
1 - ENGINE BLOCK
2 - MOUNTING BRACKET
3 - A/C COMPRESSOR
4 - BOLT (4)
24 - 50 PLUMBINGDR
A/C COMPRESSOR (Continued)

INSTALLATION
NOTE: If a replacement compressor is being
installed, be certain to check the refrigerant oil
level. See Refrigerant Oil Level in this group for the
procedures. Use only refrigerant oil of the type rec-
ommended for the compressor in the vehicle.
(1) Install the compressor onto the mounting
bracket.
(2) On the 3.7L and 4.7L engines, install and
tighten the bolts in the following sequence (Fig. 7):
²Install the inner front bolt #3 and hand tight-
ened.
²Install the outer front bolt #2 and hand tight-
ened.
²Install the rear bolt #1 and hand tightened.
²Tightened the inner front bolt #3 to 40 N´m (30
ft. lbs.).
²Tightened the outer front bolt #2 to 55 N´m (41
ft. lbs.).
²Tightened the rear bolt #1 to 55 N´m (41 ft. lbs.).
(3) For the 5.7L Hemi engine, install and tighten
the bolts in the following sequence (Fig. 8):
²Install the two long bolts into the mounting
bracket and hand tightened.
²Install the rear bolt and hand tightened.²Tightened the two long bolts to 40 N´m (30 ft.
lbs.).
²Tightened the rear bolt to 55 N´m (41 ft. lbs.).
(4) For the 5.7L Hemi engine, install the generator
and A/C compressor support bracket and retaining
nuts and bolts. Tighten the nuts and bolts securely.
(5) For the 5.9L diesel engine, install and tighten
the bolts in the following sequence (Fig. 9):
²Install the four bolts into the mounting bracket
and hand tightened.
²Tightened the four bolts to 24 N´m (17 ft. lbs.).
(6) Remove the tape or plugs from the opened
refrigerant line fittings and compressor ports.
(7) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the suction and
discharge line fittings. Use only the specified O-rings
as they are made of a special material for the R-134a
system. Use only refrigerant oil of the type recom-
mended for the A/C compressor in the vehicle.
(8) Install the suction and discharge line fittings
onto the compressor.
(9) Install the bolt or nuts (depending on engine
application) that secure the suction and discharge
line fittings to the compressor. Tighten the bolt or
nuts to 28 N´m (20 ft. lbs.).
(10) Connect the wire harness connector to the
compressor clutch coil.
Fig. 7 A/C Compressor - 3.7L Shown, 4.7L Typical
1 - BOLT #1
2 - BOLT #2
3 - BOLT #3
4 - A/C COMPRESSOR
5 - A/C CLUTCH AND PULLEY
6 - MOUNTING BRACKET
Fig. 8 A/C Compressor - 5.7L Hemi
1 - BOLT (2)
2 - A/C COMPRESSOR
3 - BOLT
4 - MOUNTING BRACKET
DRPLUMBING 24 - 51
A/C COMPRESSOR (Continued)

(11) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(12) Reconnect the battery negative cable.
(13) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(14) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
A/C CONDENSER
DESCRIPTION
The condenser is located in the air flow next to the
engine cooling radiator. The condenser is a heat
exchanger that allows the high-pressure refrigerant
gas being discharged by the compressor to give up its
heat to the air passing over the condenser fins.
OPERATION
When air passes through the condenser fins, the
high-pressure refrigerant gas within the A/C con-
denser gives up its heat. The refrigerant then con-
denses as it leaves the A/C condenser and becomes a
high-pressure liquid. The volume of air flowing over
the condenser fins is critical to the proper cooling
performance of the air conditioning system. There-fore, it is important that there are no objects placed
in front of the radiator grille openings at the front of
the vehicle or foreign material on the condenser fins
that might obstruct proper air flow. Also, any factory-
installed air seals or shrouds must be properly rein-
stalled following radiator or A/C condenser service.
The A/C condenser cannot be repaired and, if
faulty or damaged, it must be replaced.
REMOVAL
REMOVAL - 3.7, 4.7 AND 5.7L ENGINES
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the nut that secures the discharge line
fitting to the condenser inlet port (Fig. 10).
(4) Disconnect the discharge line from the con-
denser.
(5) Remove the seal from the discharge line fitting
and discard.
(6) Install plugs in, or tape over the discharge line
fitting and condenser inlet port.
(7) Remove the plastic cover from the condenser
outlet stud.
(8) Remove the nut that secures the liquid line fit-
ting to the condenser outlet.
(9) Disconnect the liquid line from the condenser.
(10) Remove the seal from the liquid line fitting
and discard.
(11) Install plugs in, or tape over the liquid line
fitting and condenser outlet port.
(12) Disconnect the wire harness connector from
the condenser cooling fan motor (Fig. 11).
(13) Remove the two bolts that secure the con-
denser to the front upper crossmember.
(14) Remove the condenser/cooling fan assembly
from the vehicle.
(15) Place the condenser/cooling fan assembly on a
flat work area and remove the four screws that
secure the cooling fan to the condenser.
(16) Separate the cooling fan from the condenser.
Fig. 9 A/C Compressor - 5.9L Diesel
1 - ENGINE BLOCK
2 - MOUNTING BRACKET
3 - A/C COMPRESSOR
4 - BOLT (4)
24 - 52 PLUMBINGDR
A/C COMPRESSOR (Continued)

REMOVAL - 5.9L DIESEL ENGINE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the plastic cover from the condenser
inlet stud.
(4) Remove the nut that secures the discharge line
fitting to the condenser inlet port (Fig. 12).
(5) Disconnect the discharge line from the con-
denser.
(6) Remove the seal from the discharge line fitting
and discard.
(7) Install plugs in, or tape over the discharge line
fitting and condenser inlet port.
(8) Remove the plastic cover from the condenser
outlet stud.
(9) Remove the nut that secures the liquid line fit-
ting to the condenser outlet.
(10) Disconnect the liquid line from the condenser.
(11) Remove the seal from the liquid line fitting
and discard.
(12) Install plugs in, or tape over the liquid line
fitting and condenser inlet port.
(13) Remove the four bolts that secure the con-
denser to the charge air cooler.
(14) Remove the condenser from the engine com-
partment.
INSTALLATION
INSTALLATION - 3.7, 4.7 AND 5.7L ENGINES
NOTE: If the condenser is replaced, add 30 millili-
ters (1 fluid ounce) of refrigerant oil to the refriger-
ant system. Use only refrigerant oil of the type
recommended for the compressor in the vehicle.
(1) Position the condenser cooling fan onto the A/C
condenser.
(2) Install and tighten the four screws that secure
the condenser cooling fan to the A/C condenser.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Carefully position the condenser/cooling fan
assembly into the engine compartment.
Fig. 10 A/C Discharge Line - 3.7L Shown, 4.7L/5.7L
Typical
1 - NUT
2 - FRONT UPPER CROSSMEMBER
3 - A/C CONDENSER
4 - NUT (2)
5 - SUCTION LINE
6 - A/C COMPRESSOR
7 - A/C PRESSURE TRANSDUCER
8 - WIRE HARNESS CONNECTOR
9 - A/C DISCHARGE LINE
Fig. 11 Condenser/Cooling Fan Assembly
1 - LH MOUNTING BOLT
2 - FRONT UPPER CROSSMEMBER
3 - LOWER MOUNTING FLANGE
4 - UPPER MOUNTING SCREW (2)
5 - LOWER MOUNTING SCREW (2)
6 - MOUNTING TABS
7 - CONDENSER COOLING FAN MOTOR
8 - COOLING FAN WIRE CONNECTOR
9 - RH MOUNTING BOLT
DRPLUMBING 24 - 53
A/C CONDENSER (Continued)

(4) Align the condenser lower mounting tabs to the
mounting flanges.
(5) Install the two bolts that secure the condenser/
cooling fan assembly to the upper front crossmember.
Tighten the bolts to 10.5 N´m (95 in. lbs.).
(6) Connect the wire harness connector to the con-
denser cooling fan motor.
(7) Remove the tape or plugs from the liquid line
fitting and condenser outlet port.
(8) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
Use only the specified O-ring as it is made of a spe-
cial material for the R-134a system. Use only refrig-
erant oil of the type recommended for the A/C
compressor in the vehicle.
(9) Connect the liquid line to the condenser outlet
port.
(10) Install and tighten the nut that secures the
liquid line fitting to the condenser. Tighten the nut to
20 N´m (180 in. lbs.).
(11) Install the plastic cover onto the condenser
outlet stud.
(12) Remove the tape or plugs from the discharge
line fitting and condenser inlet port.(13) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting. Use only the specified O-ring as it is made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the A/C
compressor in the vehicle.
(14) Connect the discharge line to the condenser
inlet port.
(15) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 20 N´m (180 in. lbs.).
(16) Reconnect the battery negative cable.
(17) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(18) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
INSTALLATION - 5.9L DIESEL ENGINE
NOTE: If the condenser is replaced, add 30 millili-
ters (1 fluid ounce) of refrigerant oil to the refriger-
ant system. Use only refrigerant oil of the type
recommended for the compressor in the vehicle.
(1) Position the condenser into the engine compart-
ment.
(2) Install the four bolts that secure the condenser
to the charge air cooler. Tighten the bolts to 10.5 N´m
(95 in. lbs.).
(3) Remove the tape or plugs from the liquid line
fitting and condenser outlet port.
(4) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the liquid line fitting.
Use only the specified O-ring as it is made of a spe-
cial material for the R-134a system. Use only refrig-
erant oil of the type recommended for the A/C
compressor in the vehicle.
(5) Connect the liquid line to the condenser outlet
port.
(6) Install and tighten the nut that secures the liq-
uid line fitting to the condenser. Tighten the nut to
20 N´m (180 in. lbs.).
(7) Install the plastic cover onto the condenser out-
let stud.
(8) Remove the tape or plugs from the discharge
line fitting and condenser inlet port.
(9) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting. Use only the specified O-ring as it is made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the A/C
compressor in the vehicle.
Fig. 12 Condenser - 5.9L Diesel Engine
1 - DISCHARGE LINE
2 - MOUNTING BOLT
3 - LIQUID LINE
4 - MOUNTING BOLT
5 - A/C CONDENSER
6 - MOUNTING BOLT
7 - MOUNTING BOLT
24 - 54 PLUMBINGDR
A/C CONDENSER (Continued)

(10) Connect the discharge line to the condenser
inlet port.
(11) Install and tighten the nut that secures the
discharge line fitting to the condenser. Tighten the
nut to 20 N´m (180 in. lbs.).
(12) Install the plastic cover onto the condenser
inlet stud.
(13) Reconnect the battery negative cable.
(14) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(15) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
A/C CONDENSER FAN
REMOVAL - 3.7, 4.7 and 5.7L ENGINES
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
WARNING) and (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - CAUTION).
(1) Disconnect and isolate the battery negative
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the nut that secures the discharge line
fitting to the condenser inlet port (Fig. 13).
(4) Disconnect the discharge line from the con-
denser.
(5) Remove the seal from the discharge line fitting
and discard.
(6) Install plugs in, or tape over the discharge line
fitting and condenser inlet port.
(7) Remove the plastic cover from the condenser
outlet stud.
(8) Remove the nut that secures the liquid line fit-
ting to the condenser outlet.
(9) Disconnect the liquid line from the condenser.
(10) Remove the seal from the liquid line fitting
and discard.
(11) Install plugs in, or tape over the liquid line
fitting and condenser inlet port.
(12) Disconnect the wire harness connector from
the condenser cooling fan motor (Fig. 14).
(13) Remove the two bolts that secure the con-
denser to the front upper crossmember.(14) Remove the condenser/cooling fan assembly
from the vehicle.
(15) Place the condenser/cooling fan assembly on a
flat work area and remove the four screws that
secure the cooling fan to the condenser.
(16) Separate the cooling fan from the condenser.
INSTALLATION - 3.7, 4.7 and 5.7L ENGINES
(1) Position the condenser cooling fan onto the A/C
condenser.
(2) Install and tighten the four screws that secure
the condenser cooling fan to the A/C condenser.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Carefully position the condenser/cooling fan
assembly into the engine compartment.
(4) Align the condenser lower mounting tabs to the
mounting flanges.
(5) Install the two bolts that secure the condenser/
cooling fan assembly to the upper front crossmember.
Tighten the bolts to 10.5 N´m (95 in. lbs.).
(6) Connect the wire harness connector to the con-
denser cooling fan motor.
(7) Remove the tape or plugs from the liquid line
fitting and condenser outlet port.
Fig. 13 A/C Discharge Line - 3.7L Shown, 4.7L/5.7L
Typical
1 - NUT
2 - FRONT UPPER CROSSMEMBER
3 - A/C CONDENSER
4 - NUT (2)
5 - SUCTION LINE
6 - A/C COMPRESSOR
7 - A/C PRESSURE TRANSDUCER
8 - WIRE HARNESS CONNECTOR
9 - A/C DISCHARGE LINE
DRPLUMBING 24 - 55
A/C CONDENSER (Continued)