2005 MERCEDES-BENZ SPRINTER Cool

TEMPERATURE CONTROL
DESCRIPTION
The optional rear heater-A/C unit output tempera-
ture is controlled by a thumbwheel-type control,
mounted in the switch panel on the instrument
panel. The temperature control (Fig. 10) allows the
selection of four temperature settings when the A/C
switch on the front A/C-heater control and the rear
A/C blower motor is activated.
OPERATION
With the front A/C switch and rear blower motor
activated, the rear A/C output temperature can be
selected by rotating the thumbwheel control upwards
(increase cooling) or downwards (decrease cooling).
Depending on the rear A/C temperature control posi-
tion, a temperature command signal is sent to the
rear A/C control module. The temperature of the cir-
culated internal air of the rear compartment is mea-
sured by a temperature sensor located in the rear
evaporator unit. The value of the temperature sensor
is compared in the rear A/C control module with an
adjusted value at the rear A/C temperature control.
The rear A/C temperature control cannot be
repaired and, if faulty or damaged, it must be
replaced.
DIAGNOSIS AND TESTING
Before testing the rear A/C temperature control,
verify that the front A/C system is operating correctly
by performing the ATC Function Test using the
DRBIIItscan tool. Use a volt/ohmmeter to test the
control. For circuit descriptions and diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the
rear A/C temperature control.
(3) Check for continuity between terminal 9 and
terminals 3 and 5 of the A/C temperature control. In
all instances, there should be continuity.
NOTE: To check the switch's internal circuits, con-
nect the positive lead of the ohmmeter to terminal 9
and the negative lead to terminals 3 and 5. To
check the switches integral light emitting diode,
reverse the ohmmeter leads.
(4) Check for resistance between terminal 3 and 5
of the A/C temperature control as you move the con-
trol to each temperature position. Resistance should
be present and should change for each position.
(5) If OK, test and repair the rear A/C tempera-
ture control wire harness circuits. If not OK, replace
the faulty rear A/C temperature control.
REMOVAL
NOTE: The rear A/C temperature control is used
only on models with the optional rear A/C unit.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the rear A/C temperature control from
the switch panel.
(3) Disconnect the wire harness connector from the
rear A/C temperature control and remove the control
from the vehicle.
INSTALLATION
(1) Connect the wire harness connector to the rear
A/C temperature control.
(2) Install the rear A/C temperature control into
the switch panel.
(3) Reconnect the battery negative cable.
Fig. 10 Rear A/C Temperature Control
VACONTROLS - REAR 24 - 29

(4) Remove floor distribution ducts from the center
floor distribution duct.
(5) Remove the shift mechanism (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
NAG1/SHIFT MECHANISM - REMOVAL).
(6) Remove center floor distribution duct from the
heater housing.
INSTALLATION
(1) Install the center floor distribution duct onto
the heater housing.
(2) Install the shift mechanism (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
NAG1/SHIFT MECHANISM - INSTALLATION).
(3) Install the left and right floor distribution
ducts onto the center floor distribution duct.
(4) Install the left and right floor distribution duct
retaining screws to the instrument panel support.
Tighten the screws to 2 N´m (17 in. lbs.).
(5) Install the defroster ducts (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/DE-
FROSTER DUCTS - INSTALLATION).
(6) Install the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
HVAC HOUSING
REMOVAL
The heater housing assembly must be removed
from the vehicle and the two halves of the housing
separated for service access of the heater core, evap-
orator and each of the various mode doors.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN PLUMBING BEFORE PERFORMING THE
FOLLOWING OPERATION. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION)
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY)
(2) Partially drain the engine cooling system
(Refer to 7 - COOLING/ENGINE/COOLANT - STAN-
DARD PROCEDURE).
(3) Disconnect and isolate the battery negative
cable.
(4) Remove the air cleaner housing (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(5) Remove the windshield washer reservoir (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - REMOVAL).
(6) Remove the air filter from the ventilation hous-
ing (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION/AIR FILTER - REMOVAL).
(7) Disconnect the wire harness and vacuum con-
nectors from the recirculation door actuator (Refer to
24 - HEATING & AIR CONDITIONING/CONTROLS/
RECIRCULATION DOOR ACTUATOR - REMOVAL).
(8) Disconnect the wire harness connector from the
blower motor resistor block (Refer to 24 - HEATING
& AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RESISTOR BLOCK - REMOVAL).
Fig. 6 Floor Distribution Duct, RH Shown, LH
Typical
1 - HEATER HOUSING
2 - SCREW (1)
3 - RH FLOOR DUCT
4 - CENTER FLOOR DUCT
24 - 34 DISTRIBUTION - FRONTVA
FLOOR DISTRIBUTION DUCTS (Continued)

DISASSEMBLY
(1) Remove the heater and ventilation housings
from the vehicle (Refer to 24 - HEATING & AIR
CONDITIONING/DISTRIBUTION/HVAC HOUSING
- REMOVAL).
(2) Place the heater housing in the upright posi-
tion on a work bench, making allowance for leakage
of fluids.
(3) Remove the gasket located at the evaporator
and heater core tubes and the gasket that seals the
ventilation housing to the heater housing (Fig. 9).
(4) Remove the 12 screws that secure the two
housing halves together.
(5) Remove the heater housing cover from the
heater housing.
(6) Remove the heater core from the heater hous-
ing.
(7) Remove the wire harness.
(8) Remove the three heater core tube retaining
bolts and the heater core tube assembly from the
heater core.
(9) Remove the heater core tube seals and discard.
(10) Install plug in, or tape over the opened heater
core fittings.
(11) Remove the evaporator core from the heater
housing.
ASSEMBLY
(1) Install the evaporator core into the heater
housing.
(2) Remove the tape or plugs from the heater core
fittings.
(3) Lubricate two new rubber o-ring seals with
clean engine coolant and install them onto the heater
core fitting.
(4) Connect the heater core tube assembly to the
heater core and install the three retaining bolts.
Tighten the bolts to 5 N´m (45 in. lbs.).
(5) Install the wire harness.
(6) Install the heater core into the heater housing.
(7) Install the heater housing cover onto the
heater housing.
(8) Install the 12 screws that secure the two hous-
ing halves together. Tighten the screws to 2 N´m (17
in. lbs.).
(9) Install the gasket for the evaporator and
heater core tube outlets and the gasket that seals the
ventilation housing to the heater housing.
(10) Install the heater and ventilation housings
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - INSTALLA-
TION).
INSTALLATION
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN PLUMBING BEFORE PERFORMING THE
FOLLOWING OPERATION. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTION)
NOTE: High pressures are produced in the refriger-
ant system when the air conditioning compressor is
operating. Extreme care must be exercised to make
sure that each of the refrigerant system connec-
tions is pressure-tight and leak free.
(1) Position the heater housing to the dash panel.
Be certain that the evaporator condensate drain tube
is positioned correctly.
(2) Install the heater housing retaining screws.
Tighten the screws to 4.5 N´m (40 in. lbs.).
(3) Connect the heater housing wire harness con-
nectors and install the wiring harness to the bracket.
Fig. 9 Heater Housing
1 - SCREW (12)
2 - HEATER HOUSING COVER
3 - EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
4 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - HEATER HOUSING
8 - WIRING HARNESS
9 - BOLT (3)
10 - HEATER CORE
11 - HEATER CORE TUBE ASSEMBLY
12 - HEATER CORE TUBE GASKET
13 - HEATER CORE TUBE O-RING SEAL (2)
24 - 36 DISTRIBUTION - FRONTVA
HVAC HOUSING (Continued)

(4) Connect the heater-A/C control cables to the
mode door levers (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/MODE DOOR CABLE
- INSTALLATION).
(5) Reinstall the passenger airbag bracket (Refer
to 8 - ELECTRICAL/RESTRAINTS/PASSENGER
AIRBAG - INSTALLATION).
(6) Reconnect the two bulkhead ground connection
near the instrument cluster area.
(7) Reinstall the defroster, floor distribution and
instrument panel ducts.
(8) Reinstall the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - INSTALLATION).
(9) Unplug or remove the tape from the opened
refrigerant line fittings.
(10) Lubricate two new rubber o-ring seals with
clean refrigerant oil and install them onto the evap-
orator core fittings.
(11) Connect the refrigerant line terminal block to
the evaporator tubes.
(12) Install the two bolts that secure the refriger-
ant line terminal block to the evaporator. Tighten the
bolts to 5 N´m (45 in. lbs.).
(13) Unplug or remove the tape from the heater
core hoses and tubes.
(14) Connect the heater hoses to the heater core
tubes and install the heater hose clamps.
(15) Install the ventilation housing to the dash
panel.
(16) Install the nuts and washers that secure the
ventilation housing to the dash panel. Tighten the
nuts to 5 N´m (45 in. lbs.).
(17) Connect the wire harness connectors to the
blower motor, blower motor resistor block and the
recirculation door actuator.
(18) Connect the vacuum harness connector to the
recirculation door actuator.
(19) Install the air filter into the ventilation hous-
ing (Refer to 24 - HEATING & AIR CONDITION-
ING/DISTRIBUTION/AIR FILTER -
INSTALLATION).
(20) Install the windshield washer reservoir (Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - INSTALLATION).
(21) Install the air cleaner housing (Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(22) Reconnect the battery negative cable.
(23) Refill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(24) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).(25) Charge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
(26) Start the engine and check for proper opera-
tion of the heating and air conditioning systems.
INSTRUMENT PANEL DUCTS
REMOVAL
(1) Remove the instrument panel (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL ASSEMBLY - REMOVAL).
(2) Remove the defroster ducts (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
DEFROSTER DUCTS - REMOVAL).
(3) Remove the floor distribution ducts (Refer to 24
- HEATING & AIR CONDITIONING/DISTRIBU-
TION/FLOOR DISTRIBUTION DUCTS - REMOV-
AL).
(4) If removing the right instrument panel duct,
remove the passenger air bag module and bracket
(Refer to 8 - ELECTRICAL/RESTRAINTS/PASSEN-
GER AIRBAG - REMOVAL).
(5) Remove the screws that secure the left and/or
right instrument panel duct and remove the duct(s)
as required (Fig. 10).
Fig. 10 Instrument Panel Duct - RH Shown, LH
Typical
1 - RH DEFROSTER DUCT
2 - SCREW (2)
3 - RH INSTRUMENT PANEL DUCT
4 - RH FLOOR DISTRIBUTION DUCT
5 - CENTER FLOOR DISTRIBUTION DUCT
VADISTRIBUTION - FRONT 24 - 37
HVAC HOUSING (Continued)

PLUMBING
TABLE OF CONTENTS
page page
PLUMBING
DESCRIPTION - REFRIGERANT LINE.......44
OPERATION - REFRIGERANT LINE.........44
WARNING.............................44
CAUTION
CAUTION...........................45
REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS.......................45
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS......................46
STANDARD PROCEDURE
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT..........46
STANDARD PROCEDURE - REFRIGERANT
RECOVERY..........................47
STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE...................47
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE.....................48
SPECIFICATIONS
CHARGE CAPACITY...................49
A/C COMPRESSOR
DESCRIPTION.........................49
OPERATION...........................49
DIAGNOSIS AND TESTING - COMPRESSOR
NOISE..............................49
REMOVAL.............................50
INSTALLATION.........................51
A/C CONDENSER
DESCRIPTION.........................52
OPERATION...........................52
REMOVAL.............................52
INSTALLATION.........................52
A/C DISCHARGE LINE
REMOVAL.............................53
INSTALLATION.........................54
A/C EVAPORATOR
DESCRIPTION.........................54
OPERATION...........................54
REMOVAL.............................55
INSTALLATION.........................55
A/C EXPANSION VALVE
DESCRIPTION.........................55
OPERATION...........................55
DIAGNOSIS AND TESTING - A/C EXPANSION
VALVE ..............................56REMOVAL.............................56
INSTALLATION.........................56
ELECTRIC COOLANT PUMP
DESCRIPTION.........................57
OPERATION...........................57
REMOVAL.............................57
INSTALLATION.........................57
HEATER CORE
DESCRIPTION.........................57
OPERATION...........................57
REMOVAL.............................58
INSTALLATION.........................58
LIQUID LINE
REMOVAL.............................58
INSTALLATION.........................59
REAR EVAPORATOR
REMOVAL.............................60
INSTALLATION.........................61
REAR EXPANSION VALVE
REMOVAL.............................62
INSTALLATION.........................63
RECEIVER/DRIER
DESCRIPTION.........................64
OPERATION...........................64
REMOVAL.............................64
INSTALLATION.........................64
REFRIGERANT
DESCRIPTION.........................65
OPERATION...........................65
REFRIGERANT OIL
DESCRIPTION.........................65
OPERATION...........................65
STANDARD PROCEDURE - REFRIGERANT
OIL LEVEL...........................65
SUCTION LINE
REMOVAL.............................66
INSTALLATION.........................66
WAT E R VA LV E
REMOVAL.............................67
INSTALLATION.........................67
UNDERBODY LINES
REMOVAL.............................68
INSTALLATION.........................69
VAPLUMBING 24 - 43

When it is necessary to open the refrigerant sys-
tem, have everything needed to service the system
ready. The refrigerant system should not be left open
to the atmosphere any longer than necessary. Cap or
plug all lines and fittings as soon as they are opened
to prevent the entrance of dirt and moisture. All lines
and components in parts stock should be capped or
sealed until they are to be installed.
All tools, including the refrigerant recycling equip-
ment, the manifold gauge set, and test hoses should
be kept clean and dry. All tools and equipment must
be designed for R-134a refrigerant.
DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
If the air conditioning system is not cooling prop-
erly, determine if the refrigerant system is fully-
charged. (Refer to 24 - HEATING & AIR
CONDITIONING - DIAGNOSIS AND TESTING -
A/C PERFORMANCE)
An electronic leak detector designed for R-134a
refrigerant is recommended for locating and confirm-
ing refrigerant system leaks. Refer to the operating
instructions supplied by the equipment manufacturer
for proper care and use of this equipment.
An oily residue on or near refrigerant system lines,
connector fittings, components, or component seals
can indicate the general location of a possible refrig-
erant leak. However, the exact leak location should
be confirmed with an electronic leak detector prior to
component repair or replacement.
To detect a leak in the refrigerant system, perform
one of the following procedures:
SYSTEM EMPTY
(1) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(2) Connect and dispense 0.283 kilograms (0.625
pounds or 10 ounces) of R-134a refrigerant into the
evacuated refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT SYSTEM
CHARGE)
(3) Position the vehicle in a wind-free work area.
This will aid in detecting small leaks.(4) With the engine not running, use a electronic
R-134a leak detector and search for leaks. Because
R-134a refrigerant is heavier than air, the leak detec-
tor probe should be moved slowly along the bottom
side of all refrigerant lines, connector fittings and
components.
(5) To inspect the evaporator coil for leaks, insert
the electronic leak detector probe into the center
instrument panel outlet. Set the blower motor switch
to the lowest speed position, the A/C button in the
On position, and select the Recirculation Mode.
SYSTEM LOW
(1) Position the vehicle in a wind-free work area.
This will aid in detecting small leaks.
(2) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run with the air conditioning system
turned on for five minutes.
(3) With the engine not running, use a electronic
R-134a leak detector and search for leaks. Because
R-134a refrigerant is heavier than air, the leak detec-
tor probe should be moved slowly along the bottom
side of all refrigerant lines, connector fittings and
components.
(4) To inspect the evaporator coil for leaks, insert
the electronic leak detector probe into the center
instrument panel outlet. Set the blower motor switch
to the lowest speed position, the A/C button in the
On position, and select the Recirculation Mode.
STANDARD PROCEDURE
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
24 - 46 PLUMBINGVA
PLUMBING (Continued)

(2) Open the low and high side valves and start
the charging station vacuum pump. When the suc-
tion gauge reads 88 kPa (26 in. Hg.) vacuum or
greater, close all of the valves and turn off the vac-
uum pump.
(a) If the refrigerant system fails to reach the
specified vacuum, the system has a leak that must
be corrected. (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - DIAGNOSIS AND
TESTING - REFRIGERANT SYSTEM LEAKS)
(b) If the refrigerant system maintains the spec-
ified vacuum for five minutes, restart the vacuum
pump, open the suction and discharge valves and
evacuate the system for an additional ten minutes.
(3) Close all of the valves, and turn off the charg-
ing station vacuum pump.
(4) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
CAUTION: A small amount of refrigerant oil is
removed from the A/C system each time the refrig-
erant system is recovered and evacuated. Before
charging the A/C system, you MUST replenish any
oil lost during the recovery process. Refer the
equipment manufacturer instructions for more infor-
mation.
After the refrigerant system has been tested for
leaks and evacuated, a refrigerant charge can be
injected into the system. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - SPECIFICA-
TIONS - CHARGE CAPACITY)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
PARTIAL CHARGE METHOD
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) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
The partial charge method is used to add a partial
charge to a refrigerant system that is low on refrig-
erant. To perform this procedure the evaporator inlet
and outlet tube temperatures are measured. The
temperature difference is measured with a tempera-
ture meter with one or two clamp-on thermocouple
probes. The difference between the evaporator inlet
and outlet tube temperatures will determine the
amount of refrigerant needed.
Before adding a partial refrigerant charge, check
for refrigerant system leaks. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING - DIAGNOSIS
AND TESTING - REFRIGERANT SYSTEM LEAKS)
If a leak is found, make the necessary repairs before
attempting a full or partial refrigerant charge.
(1) Attach a manifold gauge set to the refrigerant
system service ports.
(2) Attach the two clamp-on thermocouple probes
to the inlet and outlet tubes of the evaporator coil.
²If a single thermocouple probe is used, attach
the probe to the evaporator inlet tube just before the
collar of the refrigerant line connector fitting. The
probe must make contact with the bottom surface of
the evaporator inlet tube.
²If dual thermocouple probes are used, attach
probe 1 to the evaporator inlet tube, and probe 2 to
the evaporator outlet tube. Attach both probes to the
evaporator tubes just before the collar of the refrig-
erant line connector fittings. The probes must make
contact with the bottom surfaces of the evaporator
inlet and outlet tubes.
(3) Open all of the windows or doors of the passen-
ger compartment.
(4) Set the A/C button on the A/C Heater controls
to the on position, the temperature control knob in
the full cool position, select Recirculation Mode, and
place the blower motor switch in the highest speed
position.
(5) Start the engine and hold the engine idle speed
at 1,000 rpm. Allow the engine to warm up to normal
operating temperature.
(6) The compressor clutch may cycle, depending
upon ambient temperature, humidity, and the refrig-
erant system charge level.
(7) Hold the engine idle speed at 1,000 rpm.
(8) Allow three to five minutes for the refrigerant
system to stabilize, then record the temperatures of
the evaporator inlet and outlet tubes.
24 - 48 PLUMBINGVA
PLUMBING (Continued)

Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension as described in Cooling before beginning this
procedure.
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and pulley are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
to be certain that the discharge pressure does not
exceed 2760 kPa (400 psi).
(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which can
cause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAU-
TION - REFRIGERANT HOSES/LINES/TUBES
PRECAUTIONS)
(5) If the noise is from opening and closing of the
high pressure relief valve, reclaim, evacuate, and
recharge the refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT RECOVERY)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)If the high pressure relief valve still
does not seat properly, replace the a/c compressor.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C COMPRESSOR - REMOVAL)
(6) If the noise is from liquid slugging on the suc-
tion line, check the refrigerant oil level and the
refrigerant system charge. (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/REFRIGER-ANT OIL - STANDARD PROCEDURE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
SPECIFICATIONS - CHARGE CAPACITY).
(7) If the noise continues, replace the compressor
and repeat Step 1.
REMOVAL
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 the negative battery cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT RECOVERY).
(3) Remove the accessory drive belt from the com-
pressor clutch (Fig. 2).
(4) Remove the bolt that secures the suction line
fitting to the top of the compressor.
(5) Disconnect the suction line fitting from the
compressor suction port.
(6) Remove the seal from the suction line fitting
and discard.
(7) Install plugs in, or tape over the opened suc-
tion line fitting and the compressor suction port.
(8) Remove the bolt that secures the discharge line
fitting to the top of the compressor.
(9) Disconnect the discharge line fitting from the
compressor discharge port.
(10) Remove the seal from the discharge line fit-
ting and discard.
(11) Install plugs in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(12) Disconnect the engine wire harness connector
for the compressor clutch coil from the coil pigtail
wire connector on the top of the compressor.
(13) Raise the vehicle on a hoist.
(14) Support the compressor and remove the three
compressor mounting bolts.
(15) Remove the compressor from the engine com-
partment.
NOTE: If a replacement compressor is being
installed, be certain to drain and measure the refrig-
erant oil contained in the removed compressor.
This will determine how much oil the replacement
compressor must contain before it is installed
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/REFRIGERANT OIL - STANDARD PRO-
CEDURE).
24 - 50 PLUMBINGVA
A/C COMPRESSOR (Continued)