1988 JEEP CHEROKEE Service Repair Manual

of the scale, a symbol for defroster indicates defrost position. In
"BI-LEVEL" position, a mixture of floor heat and defroster air is
obtained.
The lower temperature control lever operates blend-air door
in heater core housing. At full right position, all air is directed
through heater core, providing maximum heat flow. At full left
position, all air is directed around heater core providing fresh air.
Control can be set in any intermediate position to provide a blend of
heated and unheated air. Heater must be in heat or defrost mode before
any air can enter vehicle.
TROUBLE SHOOTING
See JEEP TROUBLE SHOOTING at the end of this article.
REMOVAL & INSTALLATION
CONDENSER
Removal (Cherokee, Comanche & Wagoneer) NOTE: On these
models, condenser and receiver-drier are replaced
as a unit.
1) Drain radiator. Disconnect fan shroud and radiator hoses.
Disconnect automatic transmission cooler lines (if equipped).
Discharge A/C system using approved refrigerant recovery/recycling
equipment.
2) Disconnect A/C hoses from condenser. Unplug low pressure
switch. Remove radiator and condenser as an assembly. Detach condenser
retaining bolts. Separate condenser from radiator. Remove receiver-
drier from condenser.
NOTE: Plug receiver-drier openings whenever unit is removed from
condenser. Add 1 oz. of refrigerant oil (AMC No. 8132400) to
system when replacing condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
Removal (Wrangler)
1) Discharge system (slowly to prevent loss of compressor
oil) using approved refrigerant recovery/recycling equipment. Drain
coolant. Remove fan shroud and radiator. Disconnect pressure line at
condenser. Remove condenser mounting screws. Tilt bottom of condenser
toward engine.
2) From underside of vehicle, disconnect hose attaching
receiver-drier to evaporator. Plug all openings to prevent entry of
dirt or moisture. Remove receiver-drier and condenser assembly. Remove
receiver-drier from condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
RECEIVER-DRIER
NOTE: On Cherokee, Comanche and Wagoneer, receiver-drier is
removed with condenser and radiator as an assembly.
Removal (Wrangler)

Discharge system (slowly to prevent loss of compressor oil)
using approved refrigerant recovery/recycling equipment. Disconnect
evaporator and condenser lines from receiver-drier. Detach mounting
screws from receiver-drier bracket. Remove receiver-drier.
Installation
To install, reverse removal procedure. Evacuate, leak test,
recharge. Check A/C system for proper operation.
Fig. 1: Exploded View of Wrangler Evaporator Housing
Courtesy of Chrysler Motors.
EVAPORATOR-BLOWER HOUSING &
HEATER & EVAPORATOR CORES
NOTE: The following procedures are for vehicles with A/C-heater
systems only. For replacement of heater cores on vehicles
with heater systems only, see HEATER SYSTEMS, JEEP article.
Removal (Cherokee, Comanche & Wagoneer)
1) Disconnect battery ground. Discharge A/C system using
approved refrigerant recovery/recycling equipment. Disconnect A/C
hoses from expansion valve. Drain cooling system. Disconnect heater
hoses at core tubes. Disconnect blower motor wires and vent tube.
2) Remove console (if equipped). Remove lower instrument
panel. Disconnect electrical connectors at A/C relay, blower motor
resistors and A/C thermostat. Disconnect vacuum hose at vacuum motor.
Cut plastic retaining strap holding evaporator-blower housing to
heater core housing.
3) Disconnect blend-air heater control cable. Detach clip at
rear of blower housing flange and remove retaining screws. Remove

housing attaching nuts from studs on engine compartment side of dash
panel. Remove evaporator drain tube.
4) Remove right kick panel. Detach instrument panel support
bolt. Gently pull on right side of dash, then rotate housing downward
and toward rear of vehicle to disengage housing studs from dash panel.
Remove evaporator-blower housing.
5) To remove heater core, detach retaining screws. Remove
heater core by pulling straight out of housing. To remove evaporator
core, detach top housing retaining screws, then remove top of
evaporator housing.
6) Remove thermostatic switch and capillary tube. Detach 2
evaporator retaining screws and lift evaporator core from housing.
Remove expansion valve from evaporator.
Installation
1) To install components, reverse removal procedure. When
installing evaporator core, install thermostatic switch and capillary
tube before installing top of housing.
2) When installing heater core, ensure seal is properly
cemented in place to prevent it from moving when blower assembly is
installed. Evacuate, leak test, recharge and check A/C system
operation.
NOTE: The evaporator housing mounting location is similar to
Wrangler, except blower motor is mounted horizontally to
firewall.
Removal (Wrangler)
1) Discharge system using approved refrigerant
recovery/recycling equipment. Disconnect inlet line at compressor.
Disconnect hose, at quick-disconnect coupling, between receiver-drier
and evaporator. Remove hose clamps and dash grommet retaining screws.
See Fig. 2 .
Fig. 2: Wrangler Evaporator Housing Mounting Screw Locations
Courtesy of Chrysler Motors.
NOTE: It is not necessary to discharge system to service blower
motor. Evaporator housing may be lowered from instrument

panel to gain access to blower motor mounting screws.
2) Remove screws attaching evaporator housing to instrument
panel and mounting bracket. Lower evaporator housing and pull hoses
and grommet through opening.
Installation
To install, reverse removal procedure. Evacuate, leak test,
recharge and check A/C system for proper operation.
EXPANSION VALVE
Removal (Cherokee, Comanche & Wagoneer)
Discharge A/C system using approved refrigerant
recovery/recycling equipment. Disconnect A/C hoses from expansion
valve. Disconnect expansion valve from evaporator core inlet and
outlet tubes. Remove expansion valve.
Installation
To install, reverse removal procedure. Evacuate, leak test,
recharge and check A/C system operation.
NOTE: The expansion valve is pre-set and should not be adjusted. A
faulty valve requires replacement.
Removal (Wrangler)
1) Discharge system using approved refrigerant
recovery/recycling equipment. Remove evaporator housing. Remove
insulation wrapped around suction line and expansion valve.
2) Mark capillary tube location on suction line. Disconnect
inlet and outlet connections, capillary tube clamp and equalizer tube.
Remove expansion valve.
Installation
1) Clean suction line to provide positive contact with
replacement expansion valve capillary tube. Connect inlet and outlet
hoses. Clamp capillary tube securely at marked position and connect
equalizer tube.
2) Wrap expansion valve and line with insulation. Install
evaporator housing assembly. Evacuate, leak test, recharge and check
A/C system operation.
TEMPERATURE CONTROL THERMOSTAT
Removal (Cherokee, Comanche & Wagoneer)
1) Disconnect battery ground. Remove console (if equipped).
Remove lower instrument panel. Disconnect electrical connection at
thermostat. See Fig. 3.
2) Remove capillary tube retaining screw. Remove thermostat
retaining screws. Remove capillary tube from tube guide hole.
Installation
1) To install, feed capillary tube through tube guide hole
until Red tape on capillary tube just enters hole in housing. Install
capillary tube retaining screw and clip.
2) Install thermostat retaining screws and attach electrical
connection. To complete installation, reverse removal procedure.
CAUTION: Handle capillary tube with care to avoid bends or kinks
which could cause thermostat to malfunction.
Removal (Wrangler)
Remove evaporator housing assembly. Remove lower cover.

Carefully remove thermostat and capillary tube.
NOTE: On Wrangler models, servicing temperature control thermostat
requires disassembly of evaporator core housing.
Installation
To install, insert capillary tube into evaporator coil a
minimum of 2" (51 mm). See Fig. 4. Install thermostat and evaporator
housing lower cover.
Fig. 3: Capillary Tube & Temperature Control Thermostat Locations
Cherokee, Comanche and Wagoneer locations are shown.

Fig. 4: Wrangler Capillary Tube Position
Courtesy of Chrysler Motors.
TROUBLE SHOOTING

Fig. 5: Jeep Trouble Shooting Chart

Fig. 6: Jeep Trouble Shooting Flow Chart









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Does The Blower Turn?