2002 JEEP LIBERTY blend door motor

DIAGNOSIS AND TESTING - HEATER
PERFORMANCE
Before performing the following tests, refer to Cool-
ing for the procedures to check the radiator coolant
level, serpentine drive belt tension, radiator air flow
and the radiator fan operation. Also be certain that
the accessory vacuum supply line is connected at the
engine intake manifold.
MAXIMUM HEATER OUTPUT
Engine coolant is delivered to the heater core
through two heater hoses. With the engine idling atnormal operating temperature, set the temperature
control knob in the full hot position, the mode control
switch knob in the floor heat position, and the blower
motor switch knob in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged at the HVAC housing floor
outlets. Compare the test thermometer reading to the
Temperature Reference chart.
Temperature Reference
Ambient Air Temperature15.5É C
(60É F)21.1É C
(70É F)26.6É C
(80É F)32.2É C
(90É F)
Minimum Air Temperature at
Floor Outlet52.2É C
(126É F)56.1É C
(133É F)59.4É C
(139É F)62.2É C
(144É F)
If the floor outlet air temperature is too low, refer
to Cooling to check the engine coolant temperature
specifications. Both of the heater hoses should be hot
to the touch. The coolant return heater hose should
be slightly cooler than the coolant supply heater
hose. If the return hose is much cooler than the sup-
ply hose, locate and repair the engine coolant flow
obstruction in the cooling system. Refer to Cooling
for the procedures.
OBSTRUCTED COOLANT FLOW Possible loca-
tions or causes of obstructed coolant flow:
²Pinched or kinked heater hoses.
²Improper heater hose routing.
²Plugged heater hoses or supply and return ports
at the cooling system connections.
²A plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is still
low, a mechanical problem may exist.
MECHANICAL PROBLEMS Possible locations or
causes of insufficient heat:
²An obstructed cowl air intake.
²Obstructed heater system outlets.
²A blend door not functioning properly.
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on theA/C Heater control panel, the following could require
service:
²The A/C Heater control.
²The blend door actuator.
²The blend door.
²Improper engine coolant temperature.
DIAGNOSIS AND TESTING - VACUUM SYSTEM
Vacuum control is used to operate the mode doors
in the heater-only and a/c heater housings. Testing of
the heater-only and A/C Heater mode control switch
operation will determine if the vacuum, electrical,
and mechanical controls are functioning. However, it
is possible that a vacuum control system that oper-
ates perfectly at engine idle (high engine vacuum)
may not function properly at high engine speeds or
loads (low engine vacuum). This can be caused by
leaks in the vacuum system, or a faulty vacuum
check valve.
A vacuum system test will help to identify the
source of poor vacuum system performance or vac-
uum system leaks. Before starting this test, stop the
engine and make certain that the problem is not a
disconnected vacuum supply tube at the engine
intake manifold vacuum tap or at the vacuum reser-
voir.
24 - 6 HEATING & AIR CONDITIONINGKJ
HEATING & AIR CONDITIONING (Continued)

(5) Connect the test set hose or probe to the open
end of the leaking circuit. The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty
disconnected component. If not OK, go to Step 6.
(6)
To locate a leak in a vacuum line, leave one end
of the line plugged and connect the test set hose or
probe to the other end of the line. Run your fingers
slowly along the line while watching the test set gauge.
The vacuum reading will fluctuate when your fingers
contact the source of the leak. To repair the vacuum
line, cut out the leaking section of the line. Then, insert
the loose ends of the line into a suitable length of 3 mil-
limeter (0.125 inch) inside diameter rubber hose.
STANDARD PROCEDURE - DIODE
REPLACEMENT
(1) Disconnect the battery negative cable and iso-
late it.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 5).
(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 connection together using rosin core
type solder only.Do not use acid core solder.
(7) Tape the diode to the harness using electrical
tape making, sure the diode is completely sealed
from the elements.
(8) Re-connect the battery negative cable, and test
affected systems.
SPECIFICATIONS
A/C APPLICATION TABLE
Item Description Notes
Vehicle KJ- Liberty
System R134a w/ fixed
orifice tube
Compressor Sanden PXF-18 SP-10 PAG oil
Freeze±up
ControlA/C low
pressure switchaccumulator
mounted
Low psi Control opens < 25 psi
- resets > 43
psi
High psi Control switch - opens
> 450-490 psi -
resets <
270-330 psidischarge line
Control Head manual type
Mode Door vacuum
Blend Door electric
Recirculation
Doorvacuum
Blower Motor hardwired to
control headresistor block
Cooling Fan viscous for
cooling, single
speed electric
for A/C
Clutch Electro-
mechanical
Control relay PCM
Draw 2 - 3.7 amps @
12V  0.5V @ 70É F
Gap 0.0169- 0.0319
DRB IIIT
Reads TPS, RPM, A/C
switch test
Actuators clutch and fan
relay
Fig. 5 DIODE IDENTIFICATION
1 - CURRENT FLOW
2 - BAND AROUND DIODE INDICATES CURRENT FLOW
3 - DIODE AS SHOWN IN THE DIAGRAMS
KJHEATING & AIR CONDITIONING 24 - 9
HEATING & AIR CONDITIONING (Continued)

CONTROLS
TABLE OF CONTENTS
page page
A/C COMPRESSOR CLUTCH
DESCRIPTION - 3.7L and 2.4L.............12
OPERATION - 3.7L and 2.4L...............12
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH COIL...........12
STANDARD PROCEDURE - A/C
COMPRESSOR CLUTCH BREAK-IN.......12
REMOVAL.............................13
INSPECTION..........................14
INSTALLATION.........................14
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY......................15
REMOVAL.............................16
INSTALLATION.........................16
A/C HEATER CONTROL
DESCRIPTION.........................16
REMOVAL.............................17
INSTALLATION.........................17
A/C HIGH PRESSURE SWITCH
DESCRIPTION.........................17
OPERATION...........................18
DIAGNOSIS AND TESTING - A/C HIGH
PRESSURE SWITCH...................18
REMOVAL.............................18
INSTALLATION.........................18
A/C LOW PRESSURE SWITCH
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - A/C LOW
PRESSURE SWITCH...................19
REMOVAL.............................19
INSTALLATION.........................19
BLEND DOOR ACTUATOR
REMOVAL.............................20
INSTALLATION.........................20BLOWER MOTOR RELAY
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - BLOWER
MOTOR RELAY.......................21
REMOVAL.............................21
INSTALLATION.........................22
BLOWER MOTOR RESISTOR
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR....................22
REMOVAL.............................22
INSTALLATION.........................22
BLOWER MOTOR SWITCH
DESCRIPTION.........................23
OPERATION...........................23
DIAGNOSIS AND TESTING - BLOWER
MOTOR SWITCH......................23
REMOVAL.............................23
INSTALLATION.........................23
MODE DOOR ACTUATOR
REMOVAL
REMOVAL - PANEL DOOR ACTUATOR.....24
REMOVAL - FLOOR - DEFROST DOOR
ACTUATOR..........................24
INSTALLATION
INSTALLATION - PANEL DOOR ACTUATOR . 25
INSTALLATION - FLOOR - DEFROST DOOR
ACTUATOR..........................25
RECIRCULATION DOOR ACTUATOR
REMOVAL.............................26
INSTALLATION.........................26
VACUUM CHECK VALVE
DESCRIPTION.........................28
OPERATION...........................28
REMOVAL.............................28
INSTALLATION.........................28
KJCONTROLS 24 - 11

(2) Install and tighten the a/c low pressure switch
on the accumulator fitting. The switch should be
hand-tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the a/c
low pressure switch.
(4) Connect the battery negative cable.
BLEND DOOR ACTUATOR
REMOVAL
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.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove A/C housing from vehicle(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(3) Remove the screws that secure the blend door
actuator to the top of the HVAC housing. (Fig. 14).
(4) Remove the blend door actuator.
INSTALLATION
(1) Install the blend door actuator in place.
(2) Install and tighten the screws that secure the
blend door actuator to the housing. Tighten the
mounting screws to 2.4 ( .34) N´m (21 ( 3) in. lbs.).
(3) Install the HVAC housing into the vehicle(Re-
fer to 24 - HEATING & AIR CONDITIONING/DIS-
TRIBUTION/HVAC HOUSING - INSTALLATION).
(4) Install the blend door actuator electrical con-
nector from the wiring harness through the glove
box.
(5) Connect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is a International Stan-
dards Organization (ISO)-type relay. The relay is a
electromechanical device that switches battery cur-
rent from a fuse in the Power Distribution Center
(PDC) directly to the blower motor. The relay is ener-
gized when the relay coil is provided a voltage signal
by the ignition switch. (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RELAY - DIAGNOSIS AND TESTING)
OPERATION
The blower motor relay is installed in a wire har-
ness connector that is secured to the passenger side
outboard end of the HVAC housing in the passenger
compartment, next to the HVAC wire harness con-
nector.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
Fig. 14 HEATER CORE REMOVAL/INSTALLATION
1 - HEATER CORE
2- MOUNTING SCREW HOLE
3- INLET AND OUTLET TUBES
4- VACUUM HARNESS
5- ACTUATOR SCREWS (3)
6- ELECTRIC BLEND DOOR ACTUATOR
7- MOUNTING SCREW HOLE
8- HEATER CORE RETAINER TABS (4)
24 - 20 CONTROLSKJ
A/C LOW PRESSURE SWITCH (Continued)

Fig. 21 HVAC CASE ASSEMBLY
1 - BLOWER MOTOR AND CAGE
2 - RECIRCULATION DOOR ACTUATOR LINKAGE
3 - RECIRCULATION DOOR VACUUM ACTUATOR
4 - CASE RETAINER SCREW
5 - BLEND DOOR ACTUATOR MOUNTING SCREWS
6 - ELECTRIC BLEND DOOR ACTUATOR
7 - ELECTRICAL CONNECTOR FOR BLEND DOOR ACTUATOR
8 - HEATER CORE RETAINER TABS (4) AND SCREWS (2)9 - HEATER CORE
10 - HVAC CASE RETAINER CLIP
11 - HEATER CORE INPUT AND OUTPUT CONNECTIONS
12 - EVAPORATOR CONNECTION FLANGE
13 - HVAC CASE RETAINER SCREWS
14 - HVAC HOUSING
KJCONTROLS 24 - 27
RECIRCULATION DOOR ACTUATOR (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
AIR OUTLETS
DESCRIPTION - DEMISTER OUTLETS.......29
REMOVAL - PANEL OUTLET BARRELS......29
INSTALLATION - PANEL OUTLET BARRELS . . . 29
BLOWER MOTOR
DESCRIPTION.........................30
OPERATION...........................30
DIAGNOSIS AND TESTING - BLOWER
MOTOR .............................30
REMOVAL.............................30
INSTALLATION.........................31
FLOOR CONSOLE DUCT
REMOVAL.............................31
INSTALLATION.........................31
FLOOR DUCT
REMOVAL.............................32
INSTALLATION.........................32
DEFROST - DEMISTER DUCT
REMOVAL - DEFROST DUCT/DEMISTER
ADAPTOR...........................32INSTALLATION - DEFROST/DEMISTER DUCT . 32
HVAC HOUSING
REMOVAL.............................33
DISASSEMBLY.........................34
ASSEMBLY............................34
INSTALLATION.........................34
BLEND DOOR
REMOVAL.............................35
INSTALLATION.........................35
MODE DOOR
REMOVAL
REMOVAL - DEFROST DOOR............35
REMOVAL - FLOOR - DEFROST DOOR....36
INSTALLATION
INSTALLATION - PANEL DOOR...........36
INSTALLATION - FLOOR - DEFROST DOO . . 37
RECIRC DOOR
REMOVAL.............................37
INSTALLATION.........................37
AIR OUTLETS
DESCRIPTION - DEMISTER OUTLETS
The side window demister outlets are integral to
the instrument panel end caps(Refer to 23 - BODY/
INSTRUMENT PANEL/INSTRUMENT PANEL END
CAP - REMOVAL) and (Refer to 23 - BODY/INSTRU-
MENT PANEL/INSTRUMENT PANEL END CAP -
REMOVAL).
REMOVAL - PANEL OUTLET BARRELS
(1) Use a trim stick or another suitable wide flat-
bladed tool to gently pry the panel outlet barrels out
of the panel outlet housing (Fig. 1). The barrel is
retained by a light snap fit.
INSTALLATION - PANEL OUTLET BARRELS
To install, position the barrel in the panel outlet
housing and press firmly until the barrel snaps into
place.
Fig. 1 DASH PANEL OUTLETS
1 - CENTER OUTLETS
2 - SIDE WINDOW DEMISTER OUTLETS
3 - SIDE OUTLETS
4 - WIRING FOR HVAC CONTROL ASSEMBLY
5 - WINDSHIELD DEFROSTER OUTLET
KJDISTRIBUTION 24 - 29

HVAC HOUSING
REMOVAL
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.
(1) Disconnect and isolate the battery negative
cable.(2) Remove the instrument panel from the vehi-
cle(Refer to 23 - BODY/INSTRUMENT PANEL -
REMOVAL).
(3) If the vehicle is not equipped with air condi-
tioning, go to Step 6. If the vehicle is equipped with
air conditioning, recover the refrigerant from the
refrigerant system. (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT RECOVERY)
(4) Disconnect the liquid line refrigerant line fit-
ting from the evaporator inlet tube (Fig. 5). (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE - A/C LINE COU-
PLERS)
(5) Disconnect the accumulator inlet tube refriger-
ant line fitting from the evaporator outlet tube.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - A/C LINE
COUPLERS) Install plugs in, or tape over all of the
opened refrigerant line fittings.
(6) Drain the engine cooling system(Refer to 7 -
COOLING - STANDARD PROCEDURE).
Fig. 5 HVAC CASE ASSEMBLY
1 - BLOWER MOTOR AND CAGE
2 - RECIRCULATION DOOR ACTUATOR LINKAGE
3 - RECIRCULATION DOOR VACUUM ACTUATOR
4 - CASE RETAINER SCREW
5 - BLEND DOOR ACTUATOR MOUNTING SCREWS
6 - ELECTRIC BLEND DOOR ACTUATOR
7 - ELECTRICAL CONNECTOR FOR BLEND DOOR ACTUATOR
8 - HEATER CORE RETAINER TABS (4) AND SCREWS (2)9 - HEATER CORE
10 - HVAC CASE RETAINER CLIP
11 - HEATER CORE INPUT AND OUTPUT CONNECTIONS
12 - EVAPORATOR CONNECTION FLANGE
13 - HVAC CASE RETAINER SCREWS
14 - HVAC HOUSING
KJDISTRIBUTION 24 - 33

(7) Disconnect the heater hoses from the heater
core tubes. Install plugs in, or tape over the opened
heater core tubes.
(8) Unplug the HVAC system vacuum supply line
connector from the engine side harness.
(9) Remove the nuts from the HVAC housing
mounting studs.
(10) Remove the HVAC housing from inside the
vehicle taking care not to allow any remaining cool-
ant to drain on the vehicles interior.
DISASSEMBLY
(1) Remove the HVAC housing from the vehicle
and place it on the workbench. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/HVAC
HOUSING - REMOVAL)
(2) Unplug the vacuum harness connectors from
the mode and recirculation door actuators and the
recirculation door actuator.
(3) Disengage the vacuum harness from any rout-
ing clips located on the lower half of the HVAC hous-
ing.
(4) Remove the blower motor and blower wheel
unit from the HVAC housing. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/DISTRIBUTION/
BLOWER MOTOR - REMOVAL)
(5) Pop out the grommet onl the vacuum supply
line and slide hole in housing.
(6) Carefully remove the foam seals from the
heater core and evaporator coil tube mounting flange
of the HVAC housing. If the either seal is deformed
or damaged it must be replaced.
(7) Use a screwdriver to pry off the four snap clips
that help secure the upper and lower HVAC housing
halves together.
(8) Remove the screws that secure the upper and
lower HVAC housing halves together.
(9) Carefully separate the upper HVAC housing
from the lower half.
ASSEMBLY
(1) Assemble the upper HVAC housing half to the
lower half. During assembly, be certain of the follow-
ing.
(a) That each of the mode door pivot shaft ends
and the two temperature blend door shafts are
properly engaged in there pivot holes.
(b) That the blower motor venturi ring is prop-
erly indexed and installed.
(c) If the unit is equipped with air conditioning,
that the evaporator coil tube rubber seal is prop-
erly positioned in the grooves in both the upper
and lower HVAC housing halves.
(2) Install the screws and four snap clips that
secure the upper and lower HVAC housing halves toeach other. Tighten the screws to 2.2 N´m (20 in.
lbs.).
(3) Install the blower motor and wheel unit in the
HVAC housing. (Refer to 24 - HEATING & AIR CON-
DITIONING/DISTRIBUTION/BLOWER MOTOR -
INSTALLATION)
(4) Install the foam seals on the flanges around
the heater core and evaporator coil tube mounting
flange of the HVAC housing.
(5) Insert the vacuum supply line and connector
through the foam seal on the heater core and evapo-
rator coil tube mounting flange of the HVAC housing.
Check that the vacuum grommet is securely seated
into the housing hole flange.
(6) Engage the vacuum harness to the routing
clips and plug in the vacuum harness connector at
the floor door actuator and, if the unit is so equipped,
at the recirculation air door actuator.
INSTALLATION
WARNING: IF THE VEHICLE IS EQUIPPED WITH AIR
CONDITIONING, REVIEW THE WARNINGS AND
CAUTIONS IN PLUMBING BEFORE PERFORMING
THE FOLLOWING OPERATION. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - WARNING)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION -
REFRIGERANT HOSES/LINES/TUBES PRECAU-
TIONS)
(1) Position the HVAC housing to the dash panel.
Be certain that the evaporator condensate drain tube
and the housing mounting studs are inserted into
their correct mounting holes.
(2) Install and tighten the nuts onto the HVAC
housing mounting studs. Tighten the nuts to 6.2 N´m
(55 in.lbs.).
(3) Connect the HVAC system vacuum supply line
connector.
(4) Unplug or remove the tape from the heater
core tubes. Connect the heater hoses to the heater
core tubes and fill the engine cooling system(Refer to
7 - COOLING/ENGINE - STANDARD PROCE-
DURE).
(5) If the vehicle is not equipped with air condi-
tioning, go to Step 10.
(6) Unplug or remove the tape from the liquid line
and the evaporator inlet tube fittings. Connect the
liquid line coupler to the evaporator inlet tube. (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMB-
ING - STANDARD PROCEDURE - A/C LINE COU-
PLERS)
(7) Evacuate the refrigerant system. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
24 - 34 DISTRIBUTIONKJ
HVAC HOUSING (Continued)