Great Wall. Service manual for chassis and body (2006) — page 31

AC-2

Air Conditioning System

Introduction

In case the liquid refrigerant enters into the eye or touches the

skin, the following measures shall be taken:

Wash the part where is touched by the refrigerant with a

great deal of water.

Coat the skin with the clean Vaseline.

See the doctor or go to the hospital for treatment; and

Do not try to cure it yourself.

General Introduction

1.

Take notice when handling refrigerant

General Introduction

(a)

Do not handling with refrigerant in the closed room or

near to open fire.

(b)

Safety goggles shall be worn when handling

(c)

Be careful to avoid the liquid refrigerant from entering

into your eye or touching you skin.

water

air

dust

ÅçåÇÉåëÉê

plug

2.

Take notice when changing the parts of refrigerant pipes:

(a)

The refrigerant shall be exhausted gradually before

changing.

(b)

The dismantled parts shall be covered with plug right

away so as to prevent the water or dust from entering into

the system.

(c)

Do not store the condenser or liquid tank under the

condition that the plug has been uncovered. and

(d)

Refrigerant shall be exhausted before installing the new

condenser, because the refrigerant, if not exhausted, will

eject out in gaseous form with the lubricant oil when the

plug is moved away.

3.

Take notice when fastening the connection parts:

(a)

Spread a little lubricant oil at the matching position of the

O-type ring to fasten the connection and avoid of gaseous

refrigerant leakage.

(b)

Fasten the nut with two spanners so as to avoid of the pipe

deformation.

AC-3

Air Conditioning System

Introduction

(c)

Tighten the O-ring matching position or the threaded position

to the specified moment.

4.

Take notice when connecting measuring meter at branch pipes:

(a)

Connect the end of filling hose with high speed joint to the

filling valve of compressor.

(b)

Letter

D

marked on the compressor near the auxiliary valve

represents the side of high voltage while

S

means the side of

low voltage, which shall be looked out when connecting the hose.

(c)

Fasten the bolts by hand, and

(d)

In order to prevent the hose from loosing, lubricant oil shall not

be spread at the connection position.

Remarks: after connecting the measuring meter on branch pipes to

the refrigerant container (repairing tank), the air in the hose shall be

exhausted up.

5.

Take notice when vacuumizing:

After vacuumizing for 20 min, maintain the container at certain

pressure to ensure that all air in it is exhausted up, and another

inspection shall be made to see whether there is leakage.

6.

Take notice when handling with the refrigerant container

(repairing tank):

(a)

Do not heat it.

(b)

Store the container at the place where temperature is under 40

(c)

In case of heating the repairing tank with hot water, care shall

be paid to the valves at the top of tank, do not dip them into the

water, or the water will penetrate into the cooling system.

(d)

The empty repairing tank is forbidden to reuse.

8.

Take notice when using the high-pressure air cylinder type

inspecting device:

(a)

In case the open fire is used, it is the first to ensure before using

there is no flammable material around.

(b)

Be careful because toxic gas will be produced when the

gaseous refrigerant meets with the open fire.

7.

Take notice in the A/C operation or when adding the liquid

refrigerant:

(a)

In case the gaseous refrigerant in the cooling system is

insufficient, which can lead to the compressor burns out, and

such accidents shall be avoided.

(b)

If the valve on the side of high pressure is uncovered, the

refrigerant will flow in the reverse direction, which may lead

to the break of the repairing tank, therefore, only valves on the

side of low pressure are allowed to open or closed.

(c)

If the repair tank is laid in reverse direction, and the refrigerant

is added in liquid status, the liquid refrigerant will be

compressed, which may lead to failure of the compressor,

therefore, refrigerant shall be inflated in the gaseous status.

(d)

Be careful not over-inflate the gaseous refrigerant, otherwise,

such failures as insufficient cooling, increase of oil consuming

or over heat of engine will be followed.

under 40

incorrect

correct

measuring meter of branch pipe

loose

over-fastened

A/C operation

AC-4

Electric Circuit Diagram of Air

Conditioning System

Electric circuit diagram of air-conditioning system (continued)

Dr

fuse

A/C switch

pressure switch

engine wire
harness

air blower

speed-adjusting

module

wind speed switch

M

2

2

2

2

2

2

2

O

2

4

4

4

4

4

Q

4

4

4

3

3

3

3

3

3

3

3

P

5

5

5

5

5

5

5

R

1

1

N

1

1

1

1

N

6

6

6

6

6

S

7

7

T

U

8

8

9

9

10

10

11

12

13

ignition switch

pressure switch

A/C switch

speed adjusting

module of air blower

socket connectors of engine wire harness

wind speed switch

lk

^``

pq

fuse

ignition switch

air-conditioning relay

fuse

battery

AC-5

Electric Circuit Diagram of Air

Conditioning System

SF

ST

fuse

three-state pressure switch

cold-hot
servomotor

circular
servomotor

mode
servomotor

main air-conditioning

control panel

speed
adjusting
module

air blower

b`r

power resistor

water
valve

M

j

j

j

M

ACC ON

+12V

5

R

R

5

5

5

5

5

5

5

P

P

P

P

3

3

3

3

3

3

3

3

3

1

1

1

1

1

1

1

N

N

N

1

2

2

2

2

2

2

2

O

O

O

O

4

4

4

4

4

4

4

Q

Q

Q

Q

4

6

6

6

6

6

6

S

S

6

S

6

7

7

7

8

8

8

9

9

9

10

10

10

11

11

12

13

14

15

16

17

18

19

20

20

21

22

23

24

23

ignition switch

modular air-door motor cold-hot air-door motor

air-in motor

three-stage

pressure switch

speed adjusting

modul

air conditioning

ignition switch

small light relay

fuse

fuse

electronic fan

water temperature relay

fuse

compressor relay

electromagnetic

fan relay

compressor clutch

24

Electric circuit diagram of air-conditioning system (continued)

battery

18

5

17

16

3

15

19

14

22

1

13

AC-6

Air-Conditioning System

(Electric Circuit Diagram)

S

SL SK SJ

fuse

air-conditioning

request relay

connect with ECU

fuse

ECU

^``lkpq

4

5

1

2
4 5 6

3 2

3 6

5 4

2

1

1

2

1

3

2

ignition switch

speed adjusting module

air blower

A/C SWITCH

pressure switch

1

2

3

4

5

6

7

8

1

2

3

4

5

6

1

2

3

4

5

6

1

2

1

2

3

1

2

compressor

electromagnetic fan relay

compressor relay

pressure switch

fuse

fuse

electromagnetic fan

air-conditioning

request relay

A/Cswitch

blower

air-volume switch

speed-adjusting resistance

heat-sensitive resistance

blower relay

charging indicating lamp

ignition switch

air-volume switch

Electric circuit diagram of air-conditioning system (continued)

battery

ECU

AC-7

Air-Conditioning System

(Electric Circuit Diagram)

compressor

compressor relay

fuse

rearignition switch

electromagnetic

cutoff valve

rear speed-adjusting
resistance

temperature controller

rear wind-velocity switch

rear air-conditioning relay

air blower

electromagnetic fan relay

electromagnetic fan

air-conditioning request relay

A/C switch

R

ECU

pressure switch

speed-adjusting resistance

air

blower

blower relay

(electricity-connecting and
charging indicating lamp

air-conditioning

request relay

connect with ECU

2

1

3

1

2

3

3

3

2

2

1

1

4

4

4

4

1

1

2

2

3

3

5

5

5

6

6

6

4

fuse

1

1

1

1

1

1

1

1

2

2

2

2

2

2

2

2

3

3

3

3

3

3

3

3

4

4

4

4

4

4

5

5

5

5

6

6

6

6

7

7

8

8

SY

ST

ACC

ON

rearignition

switch

temperature

controller

rear wind-

velocity switch

rear speed-

adjusting resistance

speed-adjusting

resistance

air-volume

switch

A/C switch

ignition switch

ignition switch

fuse

heat-sensitive resistance

(air-volume

switch)

fuse

Electric circuit diagram of air-conditioning system (continued)

battery

ECU

AC-8

Air-Conditioning System

System Component

system component

liquid tank

compressor

condenser

HP hose

LP hose

Tightening moment for air-conditioning pipeline

Open-wrench spanner (mm)

Tightening moment(N

m)

Threaded

joint of

com-

pressor

Threaded

joint

Pressing

plate bolt

14

17

Threaded head (mm)

Open-wrench spanner (mm)

Tightening moment(N

m)

Tightening moment(N

m)

Air-conditioning pipe-line

Tightening moment(N

m)

LP hose interface

HP hose interface

25

2

35

3

18

1.5

Dr SF

SL SK SY SJ

17

19

19

19

22

24

24

27

27

27

15

3

15

3

15

3

25~30

30~35

30~35

10

14

8~12

21~25

24

14

25~30

30~35

HP hose interface

evaporator

AC-9

Air-conditioning System - General introduction

General introduction

Refrigeration cycle

1.

The refrigerant at the lower pressure side is condensed by the

compressor into the HT and HP gaseous refrigerant.

2.

These gaseous refrigerant flows into the condenser, where it is

turned into liquid refrigerant.

3.

Those liquid refrigerant flows into the liquid tank, where the

liquid refrigerant is stored and filtered so as to satisfy the

requirement of evaporator.

diaschage vent

indraft vent

compressor
curent direction

evaporator

heat

heat

expansionvalve

liquid tank

4.

The liquid refrigerant is throttled by the expansion valve to reduce the pressure, so that the liquid refrigerant is turned

into the LT and LP mixture of liquid and gaseous refrigerant.

5.

The cold and fog-like refrigerant flows into the evaporator, where it is vaporized with the given heat, which is

absorbed from the hot air flow by the evaporator core. All liquid refrigerants are turned into the gaseous refrigerant

in the evaporator, and only the heated gaseous refrigerant is absorbed into the compressor. Then repeat the above-

mentioned cycling approach.

The refrigerant released from

the evaporator expands and

inflows through the evapora-

tor pipe. During this process,

the refrigerant absorbs the

heat in the air around the ra-

diating rib and pipe and

vaporizes, so that the tem-

perature inside the vehicle

reduces gradually.

The condenser allows the heated gas-

eous refrigerant to release heat to the

cooling air of engine, therefore, the gas-

eous refrigerant is cooled and turned

into liquid state again.

The expansion valve is used

to measure the gaseous re-

frigerant entered into evapo-

rator core, which reduces the

pressure and temperature of

refrigerant gradually.

The liquid tank is used to exhaust

the water in system and to filter

the dust and dunghill. It serves as

the store to store the redundant

refrigerant.

The compressor absorbs the
gaseous refrigerant emitted
from the evaporator and com-
presses it. In doing so, the tem-
perature and pressure of gas-
eous refrigerant increases
rapidly.

AC-10

Air-conditioning System - Troubleshooting

Troubleshooting

Trouble

Reparation approaches

Page

Lack of cold air

Non-pull-in performance of electromagnetic clutch:

(a)

Break of ignition switch and fuse;

(b)

Trouble of electromagnetic clutch;

(c)

Trouble of A/C switch;

(d)

Wiring or grounding trouble;

(e)

Lack of refrigerant; and

(f)

Trouble of pressure switch.

Abnormal operation of compressor:

(a)

Looseness or break of driving belt;

(b)

Compressor trouble;

Expansion valve trouble;

Systematic leakage;

Liquid tank fusible plug melting or filtering

screen blocking;

Non-work of air blower:

(a)

Failure of A/C switch;

(b)

Failure of air blower motor, and

(c)

Wiring failure.

Change the fuse and check to see whether

there is short circuit;

Check the electromagnetic clutch;

Check the A/C switch;

Repair it as requirement;

Check the refrigerant pressure;

Check the pressure switch;

Adjust or change the driving belt;

Check the compressor;

Check the expansion valve;

Conduct lubricating test for the system

Check the liquid tank;

Check the A/C switch;

Check the air blower motor;

Conduct reparation as requirement.

Inconsecutive

cold air

Electromagnetic valve slip

Failure of expansion valve;

Wiring or connecting failure;

Over water content in system

Check the electromagnetic clutch;

Check the expansion valve;

Make reparation as requirement.

Reclaim the water first, then exhaust the

system to vacuum and inflate in the refrigerant.

Cold air occurs in

high-speed condition

Blocking of radiating face of condenser;

Driving belt slip;

Compressor failure;

Insufficient or redundant refrigerant;

Air existing in system

Check and wash the condenser

Check and change the driving belt;

Check the compressor;

Check the refrigerant quantity;

Vacuumize the system and inflate

the refrigerant;

Insufficient

cold air

Condenser blocking;

Driving belt slip;

Electromagnetic clutch failure;

Compressor failure;

Expansion valve failure;

Insufficient or redundant refrigerant;

Air existing in system;

Redundant compressor lubricant;

Liquid tank block

Check the condenser;

Check and change the driving belt;

Check the electromagnetic clutch;

Check the compressor;

Check the expansion valve;

Check the refrigerant quantity;

Reclaim the air, then vacuumize the sys-

tem and inflate the refrigerant;

Check the compressor lubricant quantity;

Check the liquid tank

Evaporator blocking or frosting

Air leakage in cooling device or air

pipeline;

Air inlet blocking;

Air blower motor failure;

Clean the evaporator radiating rib

or filter;

Make reparation as requirement

Make reparation as requirement

Change the air blower motor.

Page AC-4 to 7

Page AC-12

Page AC-4 to 7

Page AC-11

Page AC-13

Page AC-12

Page AC-16

Page AC-14

Page AC-4 to 7

Page AC-12

Page AC-16

Page AC-4 to 7

Page AC-15

Page AC-12

Page AC-12

Page AC-12

Page AC-16

Page AC-11

Page AC-14

Page AC-18

Page AC-20

Possible causes

Page AC-15

Page AC-13

Page AC-12

Page AC-11

Under-speed cold air

AC-11

Air-Conditioning System

Inspection On Refrigerant Quantity

Inspection on Refrigerant Quantity

1.

Run the engine at the speed of 1500 r/m or so (the

atmospheric temperature should be above 35

);

2.

Start the air-conditioner in the max cold air status for

several minutes;

3.

Check the refrigerant quantity.

Watch the observation window on liquid tank.

Dr SF

SL SK SY SJ

liquid tank

liquid tank

observation window

observation window

No.

1

2

3

4

5

6

Symptoms

Refrigerant quantity

Repairing approaches

Air bubble occurs in the observa-
tion window

No air bubble in observation win-
dow

No temperature difference between
the inlet and outlet of compressor

Obvious temperature difference be-

tween the inlet and outlet of compressor.

Observation window is in clear status

once the air-conditioner is turned off

There is refrigerant foam on observa-

tion window after the air-conditioner

is turned off, then the observation

window becomes clear.

Insufficient

No, normal or redundant

No, or almost no

Normal or redundant

Redundant

Normal

Check to see whether there is leakage with the

gas leakage detector

Refers 3 and 4.

Vacuumize the system and inflate the

refrigerant, then check to see whether there is

leakage with the gas leakage detector.

Refer 5 and 6

Exhaust the redundant refrigerant until the speci-

fied quantity is satisfied.

AC-12

Air-Conditioning System

Compressor

Installation of manifold gauge

Remark: Connect the manifold gauge to the auxiliary valve of

compressor.

1.

Turn off the manual valve of manifold gauge.

2.

Mount the packing hose of manifold gauge on the packing

valve.

Mount the LP hose to the LP packing valve and the HP hose to

HP packing valve. Then screw up the nuts for hose joint by

hand.

Remark: Do not coat the compressor lubricant on the connec-

tion positions.

packing hose

efrigeration system

connected to mani-

fold gauge

connect to compressor

turn off

turn off

Compressor

On vehicle inspection

1.

Mount the manifold gauge;

(see manifold gauge mount)

2.

Run the engine at the speed of 1500 r/m or so;

3.

Check the compressor according to the following items:

(a)

The HP gauge readings under the normal system should

satisfy the specified value of (1.4-1.7)MPa , that of LP

gauge should meet the specified value of (0.15-0.2)MPa .

(b)

Whether there is abnormal sound;

(c)

Whether there is leakage at the shaft oil seal.

If any problem is found, repair or change the compressor.

4.

Check the electromagnetic clutch:

(a)

Check to see whether there is lubricant trace on the

pressing plate and rotor;

(b)

Check to see whether there is noise or lubricant leakage

at the clutch bearing;

(c)

Measure the resistance between the stator coils that is set

between the clutch lead and the grounding lead with the

ohmn meter.

Standard resistance:

SL SK SJ

(3.2

.2)

Ω

Dr SF SY

(3.5

.2)

Ω

In case the requirement is not satisfied, change the compressor.

AC-13

Air-Conditioning System

Compressor

Disassemble of compressor

1.

Run the engine in the idle status for ten minutes under

the air-conditioning situation;

2.

Turn off the engine;

3.

Disconnect the cathode lead from the storage cell;

4.

Disconnect the electromagnetic clutch lead from the

matching wire;

5.

Exhaust the refrigerant from the refrigeration system;

6.

Disconnect the two hoses from the auxiliary valve of

compressor;

Cover the opening joint with cork right away to prevent the wet

gas entering in to the system.

7.

Tear down the compressor:

(a)

Tear down the fan cover;

(b)

Loosen the driving belt;

(c)

Tear down the fixing bolts of compressor bracket and the

compressor.

Mount of compressor

1.

Mount the compressor with fixing bolts;

Tightening moment

(25-30)N

m

2.

Mount the driving belt correctly;

Requirement for belt tension: the tension belt is allowed
to reduce (9-13)mm under 98N after the compressor
runs for five minutes;

3.

Connect the two hoses to the auxiliary valve of

compressor;

Tightening moment

(see page AC-8)

4.

Connect the clutch lead to the matching wire;

5.

Connect the cathode lead of storage cell to the storage

cell, and

6.

Vacuumize the system and inflate the refrigerant:

Vacuum time:

Dr SL SK SF SJ

Vacuumize for 20min and main-

tain the pressure for 30min;
SY

Vacuumize for 30min and maintain for 30min

Inflated refrigerant quantity:

Dr

(600-650)g

SL

700

0g

SK SJ

560

0g

SF

(700-720)g

SY

850

0g

correct

incorrect

incorrect

98N

AC-14

Air-Conditioning System

Liquid Tank

Liquid Tank

Check to see whether there is leakage in observation window,

fusible plug and joints;

Conduct the inspection with the gas leakage detector and, if

necessary, repair or change the liquid tank.

Dismantle of Liquid Tank

1.

Exhaust the refrigerant;

2.

Tear down the two liquid pipes from the liquid tank;

Remark: the opened joint should be plugged with cork so as to

prevent the humid air from entering into the system.

3.

Tear down the liquid tank from the tank bracket.

Mount of Liquid Tank

1.

Mount the liquid tank on the liquid tank bracket;

Remark: the cover of joint should not be take down before

connecting the pipe;

2.

Connect the two liquid pipes to the liquid tank;

Tightening moment

(See page AC-8)

3.

Vacuumize the system and inflate the refrigerant in;

Vacuumizing time:

Dr SL SK SF SJ

Vacuumize for 20 min and main-

tain the pressure for 30min;

SY

Vacuumize for 30 min and maintain the pres-

sure for 30min.

4.

Dr

(600-650)g

SL

700

0g

SK SJ

560

0g

SF

(700-720)g

SY

850

0g

liquid pipe

condenser

liquid tank

liquid pipe

liquid pipe

liquid pipe

liquid tank

condenser

SL SK SY SJ

Dr SF

AC-15

Air-Conditioning System

Condenser

Condenser

Condenser dismantle

1.

Check the radiating ribs of condenser to see whether

there is blocking or damage;

if the radiating rib is blocked, wash it with water and dry it with

compressed air.

Notice: be careful not to damage the radiating rib;

2.

Check the condenser joint to see whether there is leakage;

Make reparation as requirement;

Condenser disassembly

1.

Exhaust the refrigerant;

2.

Tear down the median mesh and the bonnet lock bracket;

3.

Disconnect the outlet hose from the entrance joint of

condenser;

4.

Tear down the liquid pipe from the outlet of liquid tank;

Remark: the opened joint should be plugged with cork so as to

prevent the humid air from entering into the system.

5.

Tear down the condenser:

Tear down the two bolts.

Condenser mount

1.

Mount the condenser

Screw on the two bolts so that the rubber washer contacts the

mounting flanges correctly.

2.

Connect the liquid pipe to the liquid tank and the outlet

hose to the condenser.

Tightening moment

(See page AC-8)

3.

Mount the median mesh and the bonnet lock bracket;

4.

vacuumize the air-conditioning system;

Vacuumizing time:

Dr SL SK SF SJ

vaccumize for 20min and main-

tain the pressure for 30min;

SY

vaccumize for 30min and maintain the pres-

sure for another 30min.

5.

Inflate the refrigerant in the air-conditioning system and

check to see whether there is air leakage:

Dr

(600-650)g

SL

700

0g

SK SJ

560

0g

SF

(700-720)g

SY

850

0g

liquid pipe

condenser

liquid tank

liquid pipe

condenser

liquid tank

SL SK SY SJ

Dr SF

liquid pipe

outlet hose

liquid pipe

AC-16

Air-Conditioning System

Refrigeration Device

Refrigeration device

On-vehicle inspection on expansion valve

1.

Check the gaseous refrigerant quantity in the refrigeration

cycle;

2.

Mount the manifold gauge;

(see Page AC-12)

3.

Run the engine;

Run the engine at a speed of 2000 r/m for five minutes.

4.

Check the expansion valve;

If the expansion valve is blocked, the LP readings will reduce

to 0 kPa, otherwise, the valve is normal.

Disassembly of Refrigeration Device

1.

Disconnect the cathode lead from the storage cell;

2.

Exhaust the refrigerant;

3.

Tear down the suction pipe from the entrance joint of

refrigeration device;

4.

Tear down the outlet pipe from the entrance joint of

refrigeration device;

Remark: the opened joint should be sealed with the cork to

prevent the humid air from entering into the system.

5.

Tear down the insulation rings from the inlet and outlet

joints.

6.

Tear down the right glove box (SY rear air-conditioner:

tear down the interior trim panel at left rear side).

7.

Disconnect the plugging element;

8.

Tear down the refrigeration device;

Tear down the three nuts.

refrigeration device

SY

interior trim panel
at left rear side

rear evaporator

AC-17

Air-Conditioning System

Refrigeration Device

evaporator housing

Dr SF

SL SK SY SJ

evaporator housing

residual liquid pipe

heat-sensitive
resistance

pressure switch

evaporator core

expansion valve

heat-sensitive

resistance

evaporator upper

housing

evaporator core

evaporator lower

housing

expansion valve

HPpressure rubber

LPpressure rubber

HP/LP pressure rubber