1992 MAZDA PROTEGE air condition

TROUBLESHOOTING GUIDE
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Symptom: Insufficient cooling.
No cooling.
Intermittent cooling.
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SIGHT GLASS
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Step 1 Checking refrigerant charge
1. Run the engine at a fast idle.
2. Operate the air conditioner at maximum cooling for a few
minutes.
3. Observe the sight glass to determine the amount of refriger-
ant and the related action as shown below.
Item Symptom Amount of refrigerant Action
1 Bubbles present in sight glass Insufficient refrigerant Check refrigerant pressure;
go to Step 2
2 No bubbles present in sight glass Too much or proper amount of Turn air conditioner OFF, and
refrigerant watch bubbles (Refer to Items 3
and 4)
__
3 Immediately after air conditioner turned Too much refrigerant Check refrigerant pressure;
OFF, refrigerant in sight glass stays clear go to Step 2
4 When air conditioner turned OFF, refrigerant
Proper amount of refrigerant Refrigerant amount normal
foams, and then sight glass becomes clear
9MUOUX-073
23UOUX-05i
Step 2 Checking refrigerant pressure
1. Connect the A/C manifold gauge set.
2. Operate the engine at 2,000 rpm and set the air condition-
er to maximum cooling.
3. Measure the low- and high-pressure sides.
(Refer to page U-37.)
Normal pressure
Low-pressure side:
147-294 kPa (1 J-3.0 kg/cm*, 21-43 psi)
High-pressure side:
1,177-1,619 kPa (12.0-16.5 kg/cm2, 171-235 psi)
4. If the pressures are not as specified, refer to the chart on
the next page and check the system.
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U TROUBLESHOOTING GUIDE
Case 1: Insufficient refrigerant
Measured pressure
Low-pressure side: Less than 78.5 kPa (0.8 kg/cm2, 11.4 psi)
High-pressure side: 785-883 kPa (8-9 kg/cm2, 114-128 psi)
Condition
l Outlet air from vents not cold.
l Bubbles seen in sight glass.
Step 1
1. Check for oil stains on the pipes, hoses and other parts, (Refer to illustration below.)
2. If oil staining is found at the connection of pipes or hoses, replace the O-ring; then, evacuate, charge,
and test the system.
3. If oil staining is not found, go to Step 2.
05UOUX-02
Step 2
1. Check for leakage from the following connections with a gas leak tester.
l Inlet and outlet of condenser.
l Inlet and outlet of receiver/drier.
l Inlet and outlet of compressor.
l Sight glass.
l Inlet and outlet of cooling unit.
2. If leakage is evident, go to Step 3.
3. If leakage cannot be found, evacuate, charge, and test the system. (System OK, but refrigerant leaked
gradually over time.)
Step 3
1. Check tightening torque of the connection where leak was detected.
2. If the connection is loose, tighten the connection to the specified torque; then evacuate, charge, and test
the system. --
3. If the connection is properly tightened, replace the O-ring; then evacuate, charge, and test the system.
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TROUBLESHOOTING GUIDE U
Case 2: Excessive refrigerant or insufficient condenser cooling
Measured pressure
Low-pressure side: Above 245 kPa (2.5 kg/cm2, 35.6 psi)
High-pressure side: Above 1,962 kPa (20 kg/cm2, 284 psi)
Condition
Insufficient cooling
Note
l If the condenser fan does not operate when the air conditioner is operating, see “Condenser
fan does not operate”; page U-8, before proceeding.
TO LOW
GAUGE
H-PRESSURE
GAUGE FITTING
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Step 1
1. Check the condenser for bent fins or damage.
Repair or replace as necessary.
2. If the condenser is OK, go to Step 2.
Step 2
1. Discharge the excess refrigerant. (Refer to page U-32.)
Warning
l Always wear gloves and eye protection when dis-
charging the refrigerant.
2. Verify that the refrigerant pressure is normal.
Case 3: Air in system
Measured pressure
Low-pressure: Above 245 kPa (2.5 kg/cm2, 35.6 psi)
High-pressure: Above 2,256 kPa (23 kg/cm2, 327 psi)
Condition
Insufficient cooling
. . CAUSE ACTION
AIR IN SYSTEM EVACUATE
SYSTEM
9MUOUX-086
Step 1
Discharge the refrigeration system. (Refer to page U-32.)
Step 2
Evacuate the system to remove all air from it.
gFI;;r; page U-33.)
Charge the system with refrigerant. (Refer to page U-33.)
Step 4
After charging, measure the refrigerant pressure.
(Refer to page U-37.)
Step 5
If the low- and high-pressure sides are still too high, replace
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23UOUX-057 the receiver/drier.

U TROU6LESHOOTlNG GUIDE
Case 4 Moisture in system
Measured pressure
Low-pressure: 50 cmHg (2.0 inHg): [Vacuum1
High-pressure: 667-l ,472 kPa (7-15 kg/cm , loo-213 psi)
Condition
Intermittent cooling
(Moisture in refrigeration system freezes in expansion valve and causes temporary blocking.
After time, ice melts and condition returns to normal.)
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CAUSE ACTION
7 r
MOISTURE
IN SYSTEM WW;MTE
-
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Case 5 No refrigerant circulation
Measurement pressure
Low-pressure: 76 cmHg (3.0 inHg) [Vacuum]
High-pressure: Below 589 kPa (6 kg/cm’, 85 psi)
Condition
Refrigerant flow obstructed by moisture or dirt, causing freezing or blockage of expansion valve
9MUOUX.090
Step 1
Discharge the refrigeration system, (Refer to page U-32.)
Step 2
Evacuate the system to remove all air and moisture from it.
$?&$r:o page U-32.)
Charge the system with refrigerant. (Refer to page U-33.)
Step 4
After charging, measure the refrigerant pressure.
(Refer to page U-37.)
Step 5
If the low- and high-pressure sides are still too high, replace
the receiver/drier.
CAUSE ACTION
f r^‘---7
MOISTURE
Id EVACUATE
IN SYSTEM SYSTEM
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CAUSE ACTION
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Step 1
Turn the air conditioner OFF for about 10 minutes. Turn the
air conditioner ON to determine whether the blockage is due
to moisture or dirt.
a) If caused by moisture
System will operate normally after being OFF for 10 minutes.
(Ice melts and relieves blockage.)
Refer to “Moisture in system”.
b) If caused by dirt
System remains abnormal after being OFF 10 minutes.
Go to Step 2.
Step 2
1. Remove the expansion valve. (Refer to page U-39.)
2. Blow out the dirt with compressed air.
3. If unable to remove the dirt, replace the expansion valve.
4. Evacuate, charge, and test the system.
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U AIR CONDITIONER
AIR CONDITIONER
STRUCTURAL VIEW
/
23UOUX-02
6. Refrigerant pressure switch No.2
Inspection.. ................................. page U-55
7. Condenser fan
Removal / Installation.. ................ page U-57
Inspection.. ................................. page U-57
8. Cooling unit
Removal / Installation .................. page U-38
Disassembly / Assembly.. ........... page U-39
Replacement.. ............................ page U-39
On-vehicle inspection ................. page U-40
Inspection ................................... page U-40
9. A/C relay
Inspection ................................... page U-56 --’
10. Condenser fan relay
Inspection ................................... page U-56 1. Compressor
Removal / Installation . . . . . . . . . . . . . . . . . . page U-41
Disassembly / Assembly... . . . . . . . . . . page U-43
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page U-50
2. Magnetic clutch
Disassembly / Assembly . . . . . . . . . . . . . page U-51
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page U-51
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page U-51
3. Condenser
Removal / Installation . . . . . . . . . . . . . . . . . . page U-53
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page U-53
4. Receiver/Drier
Removal / installation . . . . . . . . . . . . . . . . . . page U-52
5. Refrigerant pressure switch No.1
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page U-55
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AIR CONDITIONER U
REFRIGERANT SYSTEM
Safety Precaution
1. R-12 liquid refrigerant is highly volatile. A drop of it on the
skin could result in localized frostbite. When handling the
refrigerant, be sure to wear gloves.
2. If the refrigerant splashes into the eyes, wash them with clean
water immediately. Always wear goggles or glasses to pro-
tect the eyes.
9MUOUX-125 3. The R-12 container is a highly pressurized vessel.
Never subject it to high heat, and be sure that the temper-
ature where it is stored is below 52OC
(125.6OF).
4. A halide leak detector is often used to check the system
for refrigerant leakage. R-l 2, upon coming into contact with
the flame, produces phosgene, a toxic gas. Always provide
adequate ventilation.
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Refrigerant System Service Basics
Refrigerant container service valve
1. Turn the handle fully counterclockwise before connecting
the valve to the refrigerant container.
2. Turn the outlet valve counterclockwise until it reaches its
highest position.
3. Turn the outlet valve fully clockwise by hand. Connect the
center hose to the valve fitting.
4. Turn the handle clockwise to puncture the sealed can.
5. Turn the handle fully counterclockwise to fill the center hose.
Do not open the high- or low-pressure manual valves.
6. Loosen the hose nut connected to the center fitting of the
manifold gauge. Allow air to escape. Then retighten the nut.
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U AIR CONDITIONER
DRY AND WET THERMOMETER
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Performance test
After finishing repairs, conduct a performance test of the air
conditioning system as follows.
1. Connect the manifold gauge set. (Refer to page U-32.)
2. Start the engine and keep the engine speed at
1,500 rpm.
3. Operate the air conditioner at maximum cooling.
4. Open all windows and doors.
5. Place a dry-bulb thermometer in the center ventilator outlet.
6. Place a dry and wet thermometer close to the blower inlet.
7. Wait until the air conditioner outlet temperature stabilizes.
Stabilized condition
Blower inlet temperature: 25-35*C (77-95*F)
High-pressure side:
1,177-1,619 kPa (12.0-16.6 kg/cm’, 171-235 psi)
Note
l If the high-pressure side becomes too high, pour
cool water on the condenser. If It is too low, cover
the front of the condenser.
8. After the air conditioner stabilizes, read the dry and wet ther-
mometer at the air inlet.
9. Calculate the relative humidity from the chart below by com-
paring the wet- and dry-bulb readings.
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‘C ‘F
26
24
22
20
18
16
14
12
10
U
--k----
RELATIVE HUMIDITY ‘%’
I 96U16X.103
IO. Read the dry thermometer at the air outlet, and calculate
the difference between the inlet dry-bulb and outlet dry-bulb
temperatures.
11. Verify that the intersection of the relative humidity and tem-
perature difference is in the shaded zone.
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AIR CONDITIONER U / ,
9MUOUX-13
SIGHT GLASS
Checking refrigerant charge
1. Run the engine at a fast idle.
2. Operate the air conditioner at maximum cooling for a few
minutes.
3. Determine the amount of refrigerant as shown below by ob-
serving the sight glass.
Item Symptom Amount of refrigerant Action
I Bubbles present in sight glass Insufficient refrigerant Check refrigerant pressure
2 No bubbles present in sight glass Too much or proper amount of Turn air conditioner OFF, and
refrigerant watch bubbles (Refer to Items 3
and 4)
3 Immediately after air conditioner turned Too much refrigerant Check refrigerant pressure
OFF, refrigerant in sight glass stays clear
4 When air conditioner turned OFF, refrigerant Proper amount of refrigerant Refrigerant amount normal
foams, and then sight glass becomes clear
QMUOUX-140
Checking refrigerant pressure
1. Connect the manifold gauge set. (Refer to page U--32.)
2. Operate the engine at 2,000 rpm and set the air condition-
er to maximum cooling.
3. Measure the low- and high-pressure sides.
Normal pressure
Low-pressure side: 147-294 kPa
(1.5-3.0 kg/cm2, 21-43 psi)
High-pressure side: 1 ,I 77-l ,619 kPa
(12.0-l 6.5 kg/cm2, 171-235 psi)
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