air pressure switch SUBARU FORESTER 2004 Service Repair Manual

HVAC SYSTEM
(HEATER, VENTILATOR AND A/C)
AC
Page
1. General Description ....................................................................................2
2. Refrigerant Pressure with Manifold Gauge Set .........................................25
3. Refrigerant Recovery Procedure...............................................................26
4. Refrigerant Charging Procedure ...............................................................27
5. Refrigerant Leak Check ............................................................................30
6. Compressor Oil .........................................................................................31
7. Blower Motor Unit Assembly .....................................................................32
8. Blower Resistor (Manual A/C Model) ........................................................33
9. Heater Core...............................................................................................34
10. Control Unit ...............................................................................................35
11. Compressor...............................................................................................36
12. Condenser.................................................................................................37
13. Condenser (Sub Fan)................................................................................38
14. Heater Cooling Unit ...................................................................................39
15. Evaporator.................................................................................................40
16. Hose and Tube..........................................................................................41
17. Relay and Fuse .........................................................................................42
18. Pressure Switch (Triple Pressure Switch) .................................................43
19. Ambient Sensor (Auto A/C Model) ............................................................44
20. Sunload Sensor (Auto A/C Model) ............................................................45
21. Air Vent Grille ............................................................................................46
22. Heater Duct ...............................................................................................47
23. Heater Vent Duct.......................................................................................48
24. Heater Cock Solenoid Valve .....................................................................49
25. General Diagnostics ..................................................................................50

AC-3
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
General Description
 MANUAL A/C MODEL
Condenser fan (Sub fan)Motor type Magnet
Power consumption2.5 L turbo model and turbo AT model for EC and
EK:
120 W at 12 V
Other model than above:
70 W at 12 V
Fan outer diameter 320 mm (12.6 in)
Radiator fan (Main fan)Motor type Magnet
Power consumption2.5 L turbo model and turbo AT model for EC and
EK:
120 W at 12 V
Other model than above:
70 W at 12 V
Fan outer diameter 320 mm (12.6 in)
Idling speed (A/C ON) MPFI model 800±100 rpm
Triple switch
(Pressure switch)Low-pressure switch
operating pressureON → OFF177±25 kPa
(1.80±0.25 kg/cm
2, 25.60±3.56 psi)
OFF → ON206±30 kPa
(2.10±0.31 kg/cm
2, 29.86±4.41 psi)
High-pressure switch
operating pressureON → OFF2,940±200 kPa
(29.98±2.03 kg/cm
2, 426.32±28.87 psi)
OFF → ON590±200 kPa
(6.02±2.03 kg/cm
2, 85.6±28.87 psi)
Middle pressure switch
operating pressureON → OFF1370±120 kPa
(13.97±1.22 kg/cm
2, 198.65±17.35 psi)
OFF → ON1,770±100 kPa
(18.05±1.02 kg/cm
2, 256.81±14.50 psi)
Thermo control amplifier working temperature
(Evaporator outlet air)
Item Specifications
Type of air conditioner Reheat air-mix type
Cooling capacity 5.1 kW (4,386 kcal/h, 17,403 BTU/h)
RefrigerantHFC-134a (CH
2FCF3)
[600±50 g (1.32±0.11 lb)]
CompressorType Vane rotary, fix volume (DKV-14G)
Discharge
140 cm
3 (8.54 cu in)/rev
Max. permissible speed 7,000 rpm
Magnet clutchType Dry, single-disc type
Power consumption 38 W (DC12 V — 25°C)
Type of belt V-belt 4 PK
Pulley dia. (effective dia.) 125 mm (4.92 in)
Pulley ratio 1.064 Item Specifications
AC-00082
OFFON
3.0
0.3

AC-4
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
General Description
CondenserType Corrugated fin (Sub cool type)
Core face area
0.234 m
2 (2.52 sq ft)
Core thickness 16 mm (0.63 in)
Radiation area
5.6 m
2 (6.26 sq ft)
Receiver drier Effective inner capacity
220 cm
3 (13.42 cu in)
Expansion valve Type External equalizing
EvaporatorType Single tank
Dimensions (W×H×T)176.5×266×60 mm
(6.95×10.47×2.36 in)
Blower fanFan type Sirocco fan
Outer diameter×width 150×75 mm (5.91×2.95 in)
Power consumption 260 W or less at 12.5 V
Condenser fan (Sub fan)Motor type Magnet
Power consumption2.5 L turbo model and turbo AT model for EC and
EK:
120 W at 12 V
Other model than above:
70 W at 12 V
Fan outer diameter 320 mm (12.6 in)
Radiator fan (Main fan)Motor type Magnet
Power consumption2.5 L turbo model and turbo AT model for EC and
EK:
120 W at 12 V
Other model than above:
70 W at 12 V
Fan outer diameter 320 mm (12.6 in)
Idling speed (A/C ON) MPFI model 800±100 rpm
Triple switch
(Pressure switch)Low-pressure switch
operating pressureON → OFF177±25 kPa
(1.80±0.25 kg/cm
2, 25.60±3.56 psi)
OFF → ON206±30 kPa
(2.10±0.31 kg/cm
2, 29.86±4.41 psi)
High-pressure switch
operating pressureON → OFF2,940±200 kPa
(29.98±2.03 kg/cm
2, 426.32±28.87 psi)
OFF → ON590±200 kPa
(6.02±2.03 kg/cm
2, 85.6±28.87 psi)
Middle pressure switch
operating pressureON → OFF1,370±120 kPa
(13.97±1.22 kg/cm
2, 198.65±17.35 psi)
OFF → ON1,770±100 kPa
(18.05±1.02 kg/cm
2, 256.81±14.50 psi)
Thermo control amplifier working temperature
(Evaporator outlet air)Item Specifications
AC-00082
OFFON
3.0
0.3

AC-16
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
General Description
4. AIR CONDITIONING UNIT
 LHD MODEL
(1) Condenser (5) CompressorTightening torque: N·m (kgf-m, ft-lb)
(2) High-pressure hose (6) O-ringT1: 7.4 (0.75, 5.4)
(3) Low-pressure hose (7) Triple pressure switchT2: 15 (1.5, 10.8)
(4) Pipe
AC-00866
(1)(3)
(4)
(7) (5)
(2)
T1
T1T2(6) (6)
(6)(6)
(6) T2(6)

AC-25
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Refrigerant Pressure with Manifold Gauge Set
2. Refrigerant Pressure with Manifold Gauge Set
A: OPERATION
1) Place the vehicle in the shade and draftless condition.
2) Connect the manifold gauge set.
3) Open the front windows and close all doors.
4) Open the hood.
5) Increase the engine speed to 1,500 rpm.
6) Turn ON the A/C switch.
7) Turn the temperature control dial to MAX COOL.
8) Set the air inlet select switch to RECIRC position.
9) Turn the fan dial to HI.
10) Read the gauge.
Standard:
Low pressure: 127 — 196 kPa (1.3 — 2.0 kg/cm
2, 18 — 28 psi)
High pressure: 1,471 — 1, 667 kPa (15 — 17 kg/cm2, 213 — 242 psi)
Ambient temperature: 30 — 35
°C (86 — 95°F)
B: INSPECTION
Symptom Probable cause Repair order
High-pressure side is unusually high. Defective condenser fan motor
 Clogged condenser fin
 Too much refrigerant
 Air inside the system
 Defective receiver dryer Replace the fan motor.
 Clean the condenser fin.
 Discharge refrigerant.
 Replace the receiver dryer.
 After reevacuating the receiver dryer,
charge appropriate amount of refriger-
ant.
High-pressure side is unusually low. Defective compressor
 Not enough refrigerant
 Clogged expansion valve
 Expansion valve frozen temporarily by
moisture Replace the compressor.
 Check for leaks.
 Replace the expansion valve.
 Fully evacuate the expansion valve.
Low-pressure side is unusually high. Defective compressor
 Defective expansion valve
 Too much refrigerant Replace the compressor.
 Replace the expansion valve.
 Discharge refrigerant.
Low-pressure side is unusually low. Not enough refrigerant
 Clogged expansion valve
 Expansion valve frozen temporarily by
moisture
 Saturated receiver dryer  Check for leaks.
 Replace the expansion valve.
 Replace the receiver dryer.

AC-28
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Refrigerant Charging Procedure
6) Leave it at least 5 to 10 minutes after closing the
valves on low-/high-pressure sides, and then check
the low-pressure gauge reading for any changes.
When the gauge reading changes, this is a sign of
leakage. Check the pipe or hose connector points,
and repair if necessary. Repeat the procedure from
1) after repairing the faulty part.
7) If there are no leaks, further evacuate the sys-
tem 20 to 30 minutes.
8) Close all valves and stop the vacuum pump.
9) Following the can tap operation manual instruc-
tions, install it to refrigerant can.
10) Disconnect the vacuum pump from center
hose, and connect the hose to tap valve.
11) When a 13.6 kg (30 lb) refrigerant container is
used, measure the refrigerant amount in use using
a weighting scale before connecting to center hose.
12) Open the valve on HFC-134a source.13) Loosen the center hose connection on manifold
gauge (if applicable, press a purge valve on mani-
fold gauge) only for a couple of seconds to allow
the air in the center hose to escape by the refriger-
ant.
14) Make sure that the high-pressure valve of man-
ifold gauge is closed, and then open the low-pres-
sure side valve only to charge the refrigerant.
CAUTION:
Do not open the high-pressure valve. Be sure to
open the low-pressure valve.
15) Close the low-pressure valve when the low-
pressure gauge reading reaches 200 kPa (1,500
mmHg, 59.1 inHg).
16) Using a leak tester, check the system for refrig-
erant leaks.
17) After confirming that there are no leaks with the
leak test, charge the required amount of refrigerant.
18) If the HFC-134a source is empty, close the low-
pressure valve and then close the valve on can tap
before replacing the empty source. Restart charg-
ing operation after replacing the HFC-134a source
with a new one and purging.
19) Close the low-pressure valve if the charge rate
of refrigerant becomes worse.
20) Confirm that both the low-/high-pressure
valves are closed. Start the engine with A/C switch
OFF.
21) Quickly repeat A/C switch ON-OFF cycles a
few times to prevent initial compressor damage.
(1) Tap valve
(2) To center manifold hose
(1) Refrigerant container (HFC-134a)
(2) Weighting scale
AC-00214
(1)
(2)
AC-00215
(1)
(2)
(1) Open
(2) Close
AC-00216
AC-00217
(1)
(2)

AC-29
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Refrigerant Charging Procedure
22) Set up the vehicle to the following status:
 A/C switch ON
 Engine running at 1,500 rpm
 Blower speed setting to “HI”
 Temperature setting to “MAX COOL”
 Air inlet setting to “RECIRC”
 Window open
23) Open the low-pressure valve and charge the
specified amount of refrigerant.
24) Close all valves and disconnect the hoses from
service port after charging the refrigerant.
25) Install the cap to service port.

AC-36
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
Compressor
11.Compressor
A: INSPECTION
1. MAGNETIC CLUTCH CLEARANCE
1) Check the clearance of the entire circumference
around the drive plate and pulley.
Standard:
0.3 — 0.6 mm (0.0118 — 0.0236 in)
2. MAGNETIC CLUTCH OPERATION
1) Disconnect the compressor connector.
2) Connect the battery positive (+) terminal to the
No. 3 terminal of the compressor connector.
3) Make sure the magnet clutch engages.
If NG, replace the compressor.
B: REMOVAL
1) Perform the compressor oil return operation.

2) Turn the A/C switch OFF and stop the engine.
3) Using the refrigerant recovery system, discharge
refrigerant. ant Recovery Procedure.>
4) Disconnect the ground cable from battery.
5) Remove the V-belt. MOVAL, V-belt.> MOVAL, V-belt.>
6) Remove the generator. REMOVAL, Generator.>
7) Remove the low-pressure hose and high-pres-
sure hose.
8) Disconnect the compressor harness from body
harness.9) Remove the bolts to remove compressor brack-
et.
10) Remove the bolts and then separate compres-
sor and bracket.
C: INSTALLATION
1) Install in the reverse order of removal.
2) Replace the O-rings on low-/high-pressure hos-
es with new ones, then apply compressor oil.
3) When replacing compressor, adjust amount of
compressor oil. Compressor Oil.>
4) Charge refrigerant. TION, Refrigerant Charging Procedure.>
Tightening torque:
Refer to COMPONENT in General Descrip-
tion. UNIT, COMPONENT, General Description.>
NENT, General Description.>
AC-00048
AC-00049
AC-00336
AC-00051

AC-50
HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
General Diagnostics
25.General Diagnostics
A: INSPECTION
Symptom Repair order
Blower motorDoes not run.Fuse
Blower motor relay
Wiring harness
Blower motor
Blower motor resistor (Manual A/C model)
Blower switch
Noise Blower motor
CompressorDoes not run.Refrigerant
Fuse
A/C relay
Wiring harness
Magnet clutch
Compressor
Pressure switch
A/C switch
Blower switch
NoiseV- B e l t
Magnet clutch
Compressor
Condenser fanDoes not run.Fuse
Sub fan relay
Wiring harness
Noise Condenser fan motor
Cold air not emitted.Refrigerant
V- B e l t
Magnet clutch
Compressor
Pressure switch
Blower fan relay, Blower motor
A/C switch
Blower switch
Wiring harness
Heater duct
Heater vent duct
Control unit
Expansion valve
Evaporator
Air mix actuator (Auto A/C), Temperature control cable (Manual
A/C)
Warm air not emitted.Engine coolant
Aspirator hose
Blower switch
Air mix actuator (Auto A/C), Temperature control cable (Manual
A/C)
Heater core
Heater cock solenoid valve (Non-turbo model for EC/EK)

AC-3
HVAC SYSTEM (AUTO A/C)(DIAGNOSTIC)
General Description
2. General Description
A: CAUTION
1) Never connect the battery in reverse polarity.
Auto A/C control module may be destroyed instant-
ly.
2) Do not disconnect the battery terminals while the
engine is running.
A large counter electromotive force will be generat-
ed in the generator, and this voltage may damage
electronic parts such as auto A/C control module,
etc.
3) Before disconnecting the connectors of each
sensor and the auto A/C control module, be sure to
turn off the ignition switch.
Auto A/C control module may be damaged.
4) Every A/C-related part is a precision part. Do not
drop them.
5) Airbag system wiring harness is routed near the
A/C control panel (auto A/C control module) and
junction box.
CAUTION:
 For airbag system, yellow-colored wiring har-
ness and connectors are all used. Do not use
the electrical test equipment on these circuits.
 Be careful not to damage the airbag system
wiring harness when servicing the A/C control
panel (auto A/C control module) and junction
box.
B: INSPECTION
Before performing the diagnosis, check the follow-
ing items which might affect A/C system problems.
1. BATTERY
1) Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V
Specific gravity: More than 1.260
2) Check the condition of the fuses for A/C system
power supply and other fuses.
3) Check the condition of harness and harness
connector connections.
2. ASPIRATOR HOSE
1) Turn the ignition switch to ON, and press the A/
C switch.
2) Turn the temperature control dial at maximum
hot position.
3) Press the defroster switch.
4) Turn the fan speed control dial to 4th position.5) Approach a strip of paper (b) in front of the in-ve-
hicle sensor suction port (a) located in the instru-
ment lower cover, and check that air is being
sucked into the port by seeing the paper moving to-
wards port.
NOTE:
Be careful not to let the paper get sucked into port.
6) If the paper does not move at all, remove the in-
strument panel lower cover MOVAL, Instrument Panel Assembly.> and check
for improper connection of the aspirator hose (a),
in-vehicle sensor and heater unit, and repair them if
necessary.
3. A/C LINE
Check the connection for A/C line (A) and lower
side high-pressure pipe.
4. CONTROL LINKAGE
1) Check the state of mode door linkage.
2) Check the state of air mix door linkage.
3) Check the state of intake door linkage.
AC-00094
(a)
(a)
(b)
AC-00065
(a)
AC-00096
(A)