2006 MERCEDES-BENZ SPRINTER warning

mounting brackets, or a loose compressor clutch
assembly.
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
DENSO 7SBU16CA/CCOMPRESSOR
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The A/C compressor may be removed and
repositioned without disconnecting the refrigerant
lines or discharging the refrigerant system. Dis-
charging is not necessary if servicing the compres-
sor clutch, clutch coil or the engine.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(1) Disconnect and isolate the negative battery
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(3) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
(4) Disconnect the wire harness connector from the
A/C compressor clutch coil.
(5) Remove the bolts that secure the A/C suction
and discharge lines to the A/C compressor.
(6) Disconnect the A/C suction and discharge lines
from the A/C compressor and remove and discard the
O-ring seals (Fig. 4).
(7) Install plugs in, or tape over the opened refrig-
erant line fittings and the compressor ports.
(8) Raise the vehicle on a hoist.
(9) If equipped with an add-on rear A/C system,
remove the lower A/C compressor and position it out
of the way (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
REMOVAL - DENSO 10S17).
(10) Support the A/C compressor and remove the
compressor mounting bolts.
(11) Remove the A/C compressor from the engine
compartment.
VAPLUMBING 24 - 67

DENSO 10S17A/CCOMPRESSOR
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: The A/C compressor may be removed and
repositioned without disconnecting the refrigerant
lines or discharging the refrigerant system. Dis-
charging is not necessary if servicing the compres-
sor clutch, clutch coil or the engine.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Raise and support the vehicle.(4) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
(5) Disconnect the wire harness connector from the
clutch field coil of the A/C compressor (Fig. 5).
(6) Remove the bolts that secure the underbody
suction and discharge lines to the A/C compressor.
(7) Disconnect the underbody suction and dis-
charge lines from the A/C compressor and remove
and discard the O-ring seals.
(8) Install plugs in, or tape over the opened refrig-
erant line fittings and the compressor ports.
(9) Remove the bolts that secure the A/C compres-
sor to the mounting bracket.
(10) Remove the A/C compressor from the engine
compartment.
INSTALLATION
DENSO 7SBU16CA/CCOMPRESSOR
NOTE: Be certain to check the refrigerant oil level if
the A/C compressor is being replaced. See Refriger-
ant Oil Level in this group for the procedures. Use
only refrigerant oil of the type recommended for the
A/C compressor in the vehicle.
NOTE: If an internal failure of the A/C compressor
has occurred, the receiver/drier must be replaced.
(1) Position the A/C compressor in the engine com-
partment and loosely install the three compressor
retaining bolts. Tighten the bolts using the following
sequence to 20 N´m (15 ft. lbs.).
Fig. 4 Denso 7SBU16C A/C Compressor
1 - A/C COMPRESSOR
2 - O-RING SEAL
3 - A/C SUCTION LINE
4 - BOLT
5 - RETAINING CLIP
6 - BOLT
7 - A/C DISCHARGE LINE
8 - O-RING SEAL
Fig. 5 Denso 10S17 A/C Compressor
1 - REFRIGERANT LINES
2 - WIRE HARNESS CONNECTOR
3 - BOLTS (3)
4 - A/C COMPRESSOR
24 - 68 PLUMBINGVA

there are no objects placed in front of the radiator
grille openings in 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 reinstalled following radia-
tor or condenser service.
The condenser cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
(1) Disconnect and isolate the negative battery
cable.
(2) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
(3) Remove the front fascia.
(4) Remove the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(5) Remove the headlamps from their mounts.
(6) Remove the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
REMOVAL).
(7) Disconnect the A/C discharge and liquid lines
from the A/C condenser and remove and discard the
O-ring seals (Fig. 6).
(8) Install plug in, or tape over the opened liquid
line fitting and the condenser ports.
(9) Disconnect the wire harness connector from the
auxiliary fan.
(10) Remove the auxiliary fan and upper bracket
assembly.
(11) Remove the auxiliary fan lower bracket
retainers and bracket.
(12) Remove the four condenser retaining screws.
(13) Carefully remove the condenser from the vehi-
cle.
INSTALLATION
NOTE: If the A/C condenser is being replaced, add
30 milliliters (1 fluid ounce) 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 position the A/C condenser into the
engine compartment.
(2) Install the four screws that secure the A/C con-
denser. Tighten the screws to 2 N´m (17 in. lbs.).
(3) Install the lower auxiliary fan bracket and
retaining nuts. Tighten the nuts to 5 N´m (45 in.
lbs.).
(4) Install the auxiliary fan and upper bracket
assembly. Tighten the screws to 5 N´m (45 in. lbs.).
(5) Connect the wire harness connector to the aux-
iliary fan.
(6) Remove the tape or plug from the condenser
ports and the opened refrigerant line fittings.
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the refrigerant line
fittings.
(8) Connect the A/C discharge and liquid lines to
the A/C condenser.
Fig. 6 A/C Condenser
1 - SCREW (4)
2 - CONDENSER
3 - LIQUID REFRIGERANT LINE
4 - COMPRESSOR DISCHARGE LINE
5 - NUT (2)
6 - LOWER AUXILIARY FAN BRACKET
7 - NUT (2)
8 - WIRE HARNESS CONNECTOR
9 - AUXILIARY COOLING FAN
10 - SCREW (2)
24 - 70 PLUMBINGVA

(9) Install the nuts that secure the A/C discharge
and liquid lines to the A/C condenser. Tighten the
nuts to 33 N´m (24 ft. lbs.).
(10) Install the radiator crossmember (Refer to 23
- BODY/EXTERIOR/RADIATOR CROSSMEMBER -
INSTALLATION).
(11) Install the headlamps into their mounts.
(12) Install the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - INSTALLATION).
(13) Install the front fascia.
(14) Reconnect the negative battery cable.
(15) Evacuate the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE).
(16) Recharge the refrigerant system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE).
A / C DISCHARGE LINE
REMOVAL
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
(1) Disconnect and isolate 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 grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - REMOVAL).
(4) Remove the nut that secures the discharge line
fitting to the condenser on the left side of the con-
denser.
(5) Disconnect the discharge line fitting from the
condenser inlet port.
(6) Remove the seal from the discharge line fitting
and discard.
(7) Install plug in, or tape over the opened dis-
charge line fitting and the condenser inlet port.
(8) Remove the bolt that secures the discharge line
fitting to the top of the compressor (Fig. 7).
(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 plug in, or tape over the opened dis-
charge line fitting and the compressor discharge port.
(12) Disconnect the discharge line from the retain-
ing clip and remove the discharge line from the vehi-
cle.
INSTALLATION
Any kinks or sharp bends in the refrigerant plumb-
ing will reduce the capacity of the entire air condi-
tioning system. Kinks and sharp bends reduce the
flow of refrigerant in the system. A good rule for the
flexible hose refrigerant lines is to keep the radius of
all bends at least ten times the diameter of the hose.
In addition, the flexible hose refrigerant lines should
be routed so they are at least 80 millimeters (3
inches) from the exhaust manifold.
(1) Position the discharge line into the engine com-
partment.
(2) Remove the tape or plugs from the compressor
discharge port and the discharge line fitting.
(3) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(4) Connect the discharge line fitting to the com-
pressor discharge port on the top of the compressor.
(5) Install the bolt that secures the discharge line
fitting to the compressor. Tighten the bolt to 23 N´m
(17 ft. lbs.).
Fig. 7 A/C Compressor - Refrigerant Lines
1 - A/C COMPRESSOR
2 - O-RING SEAL
3 - A/C SUCTION LINE
4 - BOLT
5 - RETAINING CLIP
6 - BOLT
7 - A/C DISCHARGE LINE
8 - O-RING SEAL
VAPLUMBING 24 - 71

(6) Remove the tape or plugs from the condenser
inlet port and the discharge line fitting.
(7) Lubricate a new rubber O-ring seal with clean
refrigerant oil and install it on the discharge line fit-
ting.
(8) Connect the discharge line fitting to the con-
denser inlet port.
(9) Install the nut that secures the discharge line
fitting to the condenser. Tighten the nut to 33 N´m
(24 ft. lbs.).
(10) Install the grille (Refer to 23 - BODY/EXTE-
RIOR/GRILLE - INSTALLATION).
(11) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM EVACUATE)
(12) Charge the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
(13) Reconnect the negative battery cable.
A/CEVAPORATOR
DESCRIPTION
The A/C evaporator for the heating-A/C system is
located within the HVAC housing, behind the instru-
ment panel (Fig. 8). The A/C evaporator is positioned
within 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 compres-
sor is engaged and circulating refrigerant through
the A/C evaporator.
The A/C evaporator tubes are connected and sealed
to the A/C expansion valve by use of rubber O-rings
and a tapping block.
The A/C evaporator is serviced by removing and
disassembling the HVAC housing.
OPERATION
Refrigerant enters the evaporator from the expan-
sion valve as a low-temperature, low-pressure liquid.
As air flows over the fins of the 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 vapor-
ize. The refrigerant becomes a low-pressure gas
before it leaves the evaporator.
The evaporator cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
Fig. 8 Front A/C Evaporator
1 - A/C EVAPORATOR
2 - EVAPORATOR TUBES
3 - TAPPING BLOCK
24 - 72 PLUMBINGVA

WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
(1) Remove the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(2) Disassemble the HVAC housing to access the
A/C evaporator (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/HVAC HOUSING -
DISASSEMBLY).
(3) Lift the A/C evaporator out of the lower half of
the HVAC housing (Fig. 9).
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 thetype recommended for the A/C compressor in the
vehicle.
(1) Install the A/C evaporator into the lower half of
the HVAC housing.
(2) Assemble the HVAC housing (Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Install the HVAC housing (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - INSTALLATION).
A / C EXPANSION VALVE
DESCRIPTION
The A/C expansion valve controls the amount of
refrigerant entering the A/C evaporator and is of a
thermostatic expansion valve (TXV) design (Fig. 10).
The A/C expansion valve consists of an aluminum
H-valve type body with an integral thermal sensor.
The A/C expansion valve is located at the dash
panel between the A/C refrigerant lines and the A/C
evaporator.
OPERATION
High-pressure, high temperature liquid refrigerant
from the liquid line passes through the expansion
valve orifice, converting it into a low-pressure, low-
temperature mixture of liquid and gas before it
enters the A/C evaporator. A thermal sensor in the
A/C expansion valve monitors the temperature of the
refrigerant leaving the A/C evaporator and adjusts
the orifice size at the evaporator inlet to allow the
proper amount of refrigerant into the A/C evaporator
Fig. 9 HVAC Housing
1 - SCREW (12)
2 - UPPER HOUSING
3 - A/C EVAPORATOR
4 - EVAPORATOR O-RING SEAL (2)
5 - EVAPORATOR GASKET
6 - VENTILATION HOUSING GASKET
7 - LOWER 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)
Fig. 10 Front A/C Expansion Valve
1 - A/C EXPANSION VALVE
2 - THERMAL SENSOR
VAPLUMBING 24 - 73

in order to meet vehicle cooling requirements. Con-
trolling the refrigerant flow through the A/C evapo-
rator ensures that none of the refrigerant leaving the
evaporator is still in a liquid state, which could cause
damage to the A/C compressor.
The A/C expansion valve is factory calibrated and
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.
DIAGNOSIS AND TESTING
A / C EXPANSION VALVE
The A/C expansion valve is located on the engine
side of the dash panel near the shock tower.
The A/C expansion valve can fail in three different
positions (open, closed or restricted).
In an Open Position: this will result in a noisy A/C
compressor or no cooling. The cause can be broken
spring, broken ball or excessive moisture in the A/C
system. If the spring or ball are found to be defective,
replace the A/C expansion valve. If excessive mois-
ture is found in the A/C system, recycle the refriger-
ant.
In a Closed Position: There will be low suction
pressure and no cooling. This may be caused by a
failed power dome or excessive moisture in the A/C
system. If the power dome on the A/C expansion
valve is found to be defective replace the A/C expan-
sion valve. If excessive moisture is found recycle the
refrigerant.
A Restricted Orifice: There will be low suction
pressure and no cooling. This may be caused by
debris in the refrigerant system. If debris is believed
to be the cause, recycle the refrigerant and replace
the A/C expansion valve and the receiver-drier.
REMOVAL
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
(1) Recover the refrigerant from the A/C system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM RECOVERY).
(2) Disconnect and isolate the negative battery
cable.
(3) Remove the nut that secures the suction and
liquid line fittings to the stud on the A/C expansion
valve (Fig. 11).(4) Disconnect the suction and liquid lines from
the expansion valve.
(5) Remove the seals from the suction and liquid
line fitting and discard.
(6) Install plugs in, or tape over the opened liquid
and suction line fittings and both expansion valve
ports.
(7) Remove the two bolts that secure the expan-
sion valve to the evaporator tube tapping plate.
(8) Remove the expansion valve from the evapora-
tor tube tapping plate.
(9) Remove the seals from the evaporator inlet and
outlet tube fittings and discard.
(10) Install plugs in, or tape over the opened evap-
orator inlet and outlet tube fittings and both expan-
sion valve ports.
INSTALLATION
(1) Remove the tape or plugs from the tapping
plate evaporator inlet and outlet tube fittings and
both ports on the back of the A/C expansion valve.
(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the tapping plate
evaporator inlet and outlet tube fittings.
(3) Position the A/C expansion valve onto the tap-
ping plate evaporator inlet and outlet tube fittings.
Fig. 11 A/C Expansion Valve
1 - EVAPORATOR TUBE TAPPING PLATE
2 - O-RING SEAL (2)
3 - A/C EXPANSION VALVE
4 - BOLT (2)
5 - A/C SUCTION LINE
6 - NUT
7 - A/C LIQUID LINE
8 - O-RING SEAL (2)
24 - 74 PLUMBINGVA

INSTALLATION
(1) Install the electric coolant pump and mounting
bracket onto the body studs.
(2) Install the two bracket retaining nuts. Tighten
the nuts to 5 N´m (45 in. lbs.).
(3) Using a twisting motion gently install both
hoses onto the electric coolant pump.
(4) Tighten both hose clamps securely.
(5) Connect the wire harness connector to the elec-
tric coolant pump.
(6) Reconnect the negative battery cable.
(7) Fill the engine cooling system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE - COOLING SYSTEM FILL).
HEATER CORE
DESCRIPTION
The heater core is mounted into the HVAC hous-
ing, located behind the instrument panel (Fig. 14).
The heater core is a heat exchanger made of rows of
tubes and fins. The heater core tubes are attached to
the heater core by using O-ring seals and bolts.
The heater core is serviced by removing and disas-
sembling the HVAC housing.
OPERATION
Engine coolant is circulated through the heater
hoses to the heater core whenever the heater water
valve is cycled open by the ATC A/C-heater control.
As the coolant flows through the heater core, heat
removed from the engine is transferred to the heater
core fins and tubes. Air directed through the heater
core picks up the heat from the heater core fins. The
heater water valve controls the heater output air
temperature by controlling the amount of heated
engine coolant flowing through the heater core. The
blower motor speed controls the volume of air flowing
through the HVAC housing.
The heater core cannot be repaired and, if faulty or
damaged, it must be replaced.
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, impact sensor, or instrument panel com-
ponent diagnosis or service. Disconnect and isolate
the battery negative (ground) cable, then wait two
minutes for the system capacitor to discharge
before performing further diagnosis or service. This
is the only sure way to disable the supplemental
restraint system. Failure to take the proper precau-
tions could result in accidental airbag deployment.
Fig. 13 Electric Coolant Pump
1 - HEATER HOSE
2 - HOSE CLAMP (2)
3 - HEATER HOSE
4 - ELECTRIC COOLANT PUMP
5 - WIRE HARNESS CONNECTOR
6 - NUT (2)
Fig. 14 Front Heater Core
1 - HEATER CORE
2 - BOLT (3)
3 - HEATER CORE TUBES
4 - O-RING SEALS
24 - 76 PLUMBINGVA