Content .. 583 584 585 586 ..

Jeep Wrangler TJ. Manual - part 585

Condition

Possible Causes

Correction

3. Refrigerant flow through
the A/C evaporator is
restricted.

3. See A/C Evaporator in this group. Replace the
restricted A/C evaporator, if required.

4. Faulty A/C compressor.

4. See A/C Compressor in this group. Replace
the A/C compressor, if required.

The low side pressure is
normal or slightly high, and
the high side pressure is too
high.

1. A/C condenser air flow
restricted.

1. Check the A/C condenser for damaged fins,
foreign objects obstructing air flow through the
condenser fins, and missing or improperly
installed air seals. Clean, repair, or replace
components as required.

2. Inoperative radiator
cooling fan.

2. Test the radiator cooling fan and replace, if
required. Refer to Group 7.

3. Refrigerant system
overcharged.

3. See Refrigerant System Charge in this group.
Recover the refrigerant from the refrigerant
system. Charge the refrigerant system to the
proper level, if required.

4. Air in the refrigerant
system.

4. See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.

5. Engine overheating.

5. Test the engine cooling system and repair, if
required. Refer to Group 7.

The low side pressure is too
high, and the high side
pressure is too low.

1. Accessory drive belt
slipping.

1. Inspect the accessory drive belt condition and
tension. Tighten or replace the accessory drive
belt, if required. Refer to Group 7.

2. Faulty A/C orifice tube.

2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.

3. Faulty A/C compressor.

3. See A/C Compressor in this group. Replace
the A/C compressor, if required.

The low side pressure is too
low, and the high side
pressure is too high.

1. Restricted refrigerant flow
through the refrigerant lines.

1. See Liquid Line and Suction and Discharge
Line in this group. Inspect the refrigerant lines for
kinks, tight bends or improper routing. Correct
the routing or replace the refrigerant line, if
required.

2. Restricted refrigerant flow
through the A/C orifice tube.

2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.

3. Restricted refrigerant flow
through the A/C condenser.

3. See A/C Condenser in this group. Replace the
restricted condenser, if required.

24 - 6

HEATING & AIR CONDITIONING

HEATING & AIR CONDITIONING (Continued)

HEATER PERFORMANCE

WARNING: Review safety precautions and warnings
in this group before performing this procedure
(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.

Check the coolant level, drive belt tension, radiator

air flow and fan operation. Start engine and allow to
warm up to normal operating temperature.

WARNING: Do not remove radiator cap when engine
is hot, personal injury can result.

If vehicle has been run recently, wait 15 minutes

before removing the radiator cap. Place a rag over

the cap and turn it to the first safety stop. Allow
pressure to escape through the overflow tube. When
the system pressure stabilizes, remove the cap com-
pletely.

MAXIMUM HEATER OUTPUT: TEST AND ACTION

Engine coolant is provided to the heater system by

two heater hoses. With the engine idling at normal
operating temperature, set the temperature control
to maximum heat, the mode control to the floor posi-
tion, and the blower in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged from the floor outlets. Com-
pare the test thermometer reading to the Heater
Temperature Reference chart.

HEATER TEMPERATURE REFERENCE

Ambient Air Temperature

15.5° C

(60° F)

21.1° C

(70° F)

26.6° C

(80° F)

32.2° C

(90° F)

Minimum Air Temperature at
Floor Outlet

62.2° C

(144° F)

63.8° C

(147° F)

65.5° C

(150° F)

67.2° C

(153° F)

If the floor outlet air temperature is insufficient,

check that the cooling system is operating to specifi-
cations (Refer to 7 - COOLING/ENGINE - DIAGNO-
SIS AND TESTING). Both heater hoses should be
HOT to the touch (the coolant return hose should be
slightly cooler than the supply hose). If the coolant
return hose is much cooler than the supply hose,
locate and repair the engine coolant flow obstruction
in heater system.

OBSTRUCTED COOLANT FLOW

Possible locations or causes of obstructed coolant

flow are as follows:

• Pinched or kinked heater hoses.

• Improper heater hose routing.

• Plugged heater hoses or supply and return ports

at the cooling system connections.

• Plugged heater core.
If proper coolant flow through the cooling system is

verified, and heater outlet air temperature is insuffi-
cient, a mechanical problem may exist.

MECHANICAL PROBLEMS

Possible causes of insufficient heat due to mechan-

ical problems are as follows:

• Faulty engine thermostat.

• Faulty blend door actuator.

• Obstructed fresh air intake.

• Obstructed heater system outlets.

• Faulty blend-air door.

TEMPERATURE CONTROL

If the heater outlet air temperature cannot be

adjusted with the temperature control on the A/C-
heater control panel, the following could require ser-
vice:

• Faulty blend door actuator.

• Faulty A/C-heater control.

• Faulty related wiring harness or connectors.

• Faulty blend-air door.

HEATING & AIR CONDITIONING

24 - 7

HEATING & AIR CONDITIONING (Continued)

SPECIFICATIONS

HEATING-A/C SYSTEM

A/C SYSTEM

Item

Description

Notes

A/C
Compressor

Denso 10PA17

ND-8 PAG Oil

Freeze–up
Control

A/C low
pressure switch

Input to PCM,
accumulator
mounted -
cycles A/C
clutch off below
172 kPa (25
psi) - cycles
back on above
276 kPa (40
psi)

Low psi Control

A/C low
pressure switch

Input to PCM,
opens below
172 kPa (25
psi) - resets
above 276 kPa
(40 psi)

High psi Control

A/C high
pressure switch
(4.0L engine)

Input to PCM,
A/C discarge
line mounted -
opens at
discharge
pressure above
3100 - 3375
kPa (450 - 490
psi) - resets at
1860 - 2275
kPa (270 - 330
psi)

A/C pressure
transducer
(2,4L engine)

Input to PCM,
A/C discarge
line mounted -
opens at
discharge
pressure above
2971 kPa (431
psi) and below
206 kPa (30
psi)

Item

Description

Notes

Refrigerant
Charge
Capacity

Refer to the
A/C Underhood
Specification
Label located in
the engine
compartment

R-134a
refrigerant

A/C Clutch Coil
Draw

2.0 - 3.7 amps

@ 12V ± 0.5V
@ 21° C (70° F)

A/C Clutch Air
Gap

0.35 - 0.65 mm
(0.014 - 0.026
in)

24 - 8

HEATING & AIR CONDITIONING

HEATING & AIR CONDITIONING (Continued)

FASTENER TORQUE

Description

N·m

Ft. Lbs.

In. Lbs.

All Screws NOT Listed
Below

–

A/C Compressor Shaft
Bolt

–

115

A/C Compressor Mounting
Bolts (4.0L)

45-65

35-50

–

A/C Compressor Rear
Brace Bolts (4.0L)

40-55

30-40

–

A/C Compressor Mounting
Bolts (2.4L)

–

A/C Condenser Mounting
Bolts

–

Accumulator Retaining
Band Bolt

4.5

–

Discharge Line to
Compressor Nut

–

Discharge Line to
Condenser Nut

–

105

HVAC Housing Stud Nuts

–

Liquid Line to Condenser
Nut

–

105

Refrigerant Line Bracket
Nut (4.0L)

–

Refrigerant Line to
Accumulator Nut

–

Radiator Shroud Bolts

–

Suction Line to
Compressor Nut

–

HEATING & AIR CONDITIONING

24 - 9

HEATING & AIR CONDITIONING (Continued)

Content .. 583 584 585 586 ..