Dodge Ram Truck 1500-2500-3500. Manual — part 2074

NOTE: The protective cap helps aid in service port sealing and helps protects the refrigerant system from
contamination. Remember to always reinstall the protective cap onto the service port when refrigerant sys-
tem service is complete.

6. Install the protective cap (1) onto the service port.

COUPLER-REFRIGERANT LINE

DESCRIPTION

Spring-lock type refrigerant line couplers (1 and 4) are
used to connect the A/C suction line (6) to the A/C
accumulator (5) and, the A/C accumulator and the A/C
liquid line to the A/C evaporator tubes (3). Secondary
retaining clips (2 and 7) are installed over the con-
nected couplers for added protection.

The spring-lock refrigerant line couplers require spe-
cial disconnect tools for disengaging the two coupler
halves.

OPERATION

The spring-lock type refrigerant line coupler is held
together by a garter spring (6) inside a circular cage
(7) on the male half of the fitting (1). When the two
coupler halves are connected, the flared end of the
female fitting (2) slips behind the garter spring inside
the cage on the male fitting. The garter spring and
cage prevent the flared end of the female fitting from
pulling out of the cage. Some applications use a con-
nection indicator ring (4) to help indicate when the two
coupler halves are fully connected.

Two O-rings (8) are used to seal the coupler connec-
tions. These O-rings are compatible with R-134a
refrigerant and must be replaced with O-rings made of
the same material.

A secondary retaining clip (3) is installed over the con-
nected coupler (5) for added protection.

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PLUMBING

DR/DH

REMOVAL

WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.

1. Recover the refrigerant from the refrigerant system

(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING

-

STANDARD

PROCEDURE

-

REFRIGERANT SYSTEM RECOVERY).

2. Remove the secondary retaining clip from the

spring-lock type refrigerant line coupler.

3. Fit the proper size A/C line disconnect tool (Special

Tool Kit 7193 or equivalent) over the coupler cage
(1).

4. Close the two halves of the A/C line disconnect tool

around the coupler (2).

NOTE: The garter spring may not release if the A/C
line disconnect tool is cocked while pushing it
into the coupler cage opening.

5. Push the A/C line disconnect tool into the open

side of the coupler cage to expand the garter
spring (3). Once the garter spring is expanded, pull
on the refrigerant line attached to the female half of
the coupler until the flange on the female fitting is
separated from the garter spring and cage on the male fitting.

6. Open and remove the A/C line disconnect tool from the refrigerant line coupler (4).

INSTALLATION

1. Clean any dirt or foreign material from the spring-

lock type refrigerant line coupler.

2. Check to make sure that the garter spring (6) is

located within the cage (7) of the male half of the
refrigerant line coupler (1), and that the garter
spring is not damaged.

a. If the garter spring is missing, install a new

spring by pushing it into the coupler cage
opening.

b. If the garter spring is damaged, remove it from

the coupler cage with a small hook (DO NOT
use a screwdriver) and install a new garter
spring.

CAUTION: Use only the specified O-rings as they
are made of a special material for the R-134a system. The use of any other O-rings may allow the connec-
tion to leak.

3. Install new O-rings (8) on the male half of the refrigerant line coupler.

4. Lubricate the O-rings, and the inside of the female half of the refrigerant line coupler (2) with clean R-134a refrig-

erant oil. Use only refrigerant oil of the type recommended for the A/C compressor in the vehicle.

5. Position the female half of the coupler over the male half of the coupler.

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6. Push together firmly on the two halves of the refrigerant line coupler until the garter spring in the cage on the

male half of the coupler snaps over the flanged end on the female half of the coupler.

7. Make sure that the refrigerant line coupler is fully engaged by firmly pulling the refrigerant lines away from each

other on both sides of the coupler.

8. Install the secondary retaining clip (3) over connected coupler cage (5).

9. Evacuate the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-

CEDURE - REFRIGERANT SYSTEM EVACUATE).

10. Charge the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-

CEDURE - REFRIGERANT SYSTEM CHARGE).

EVAPORATOR-A/C

DESCRIPTION

The A/C evaporator (1) for the heating-A/C system is
located within the HVAC housing, behind the instru-
ment panel. The A/C evaporator and it’s insulator (2)
are positioned in the HVAC housing so that all air
entering the housing must pass over the evaporator
fins before it is distributed through the heating-A/C
system ducts and outlets. However, air passing over
the evaporator fins will only be conditioned when the
A/C compressor is engaged and circulating refrigerant
through the A/C evaporator.

The A/C evaporator can be serviced by removing and
disassembling the HVAC housing assembly.

OPERATION

Refrigerant enters the A/C evaporator through the A/C orice tube as a low-temperature, low-pressure mixture of
liquid and gas. As air flows over the fins of the A/C evaporator, the humidity in the air condenses on the fins, and
the heat from the air is absorbed by the refrigerant. Heat absorption causes the refrigerant to boil and vaporize. The
refrigerant becomes a low-pressure gas when it leaves the A/C evaporator.

The A/C evaporator cannot be repaired and, if faulty or damaged, it must be replaced.

REMOVAL

WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering
wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the
negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before
performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to
take the proper precautions could result in accidental airbag deployment and possible personal injury or
death.

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1. Remove the HVAC housing (Refer to 24 - HEAT-

ING

&

AIR

CONDITIONING/DISTRIBUTION/

HOUSING-HVAC - REMOVAL).

2. Disassemble the HVAC housing to access the A/C

evaporator (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION/HOUSING-HVAC - DIS-
ASSEMBLY).

3. Remove the probe of the evaporator temperature

sensor (1) from the fins of the A/C evaporator (2)
and position the wire lead (3) out of the way.

4. Carefully lift the A/C evaporator out of the upper

half of the HVAC housing (4).

5. Inspect all foam seals and replace as required.

INSTALLATION

NOTE: If the A/C evaporator is being replaced, add 60 milliliters (2 fluid ounces) of refrigerant oil to the
refrigerant system. Use only refrigerant oil of the type recommended for the A/C compressor in the vehicle.

1. Carefully install the A/C evaporator (2) into the

upper half of the HVAC housing (4).

2. Install the probe of the evaporator temperature

sensor (1) between the fins of the A/C evaporator.

3. Route the wire lead for the evaporator temperature

sensor (3) into the opening located on the upper
half of the HVAC housing.

4. Assemble the HVAC housing (Refer to 24 - HEAT-

ING

&

AIR

CONDITIONING/DISTRIBUTION/

HOUSING-HVAC - ASSEMBLY).

5. Install the HVAC housing (Refer to 24 - HEATING

& AIR CONDITIONING/DISTRIBUTION/HOUSING-
HVAC - INSTALLATION).

FAN-A/C CONDENSER

REMOVAL - 3.7L/4.7L/5.7L ENGINES

WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.

DR/DH

PLUMBING

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