1992 MAZDA PROTEGE Workshop Manual

TROUBLESHOOTING GUIDE U
Step 5 Check thermoswitch
1. Turn OFF the A/C switch and set the blower switch to the
fourth position to operate the blower fan for a few minutes.
2. After a few minutes, turn OFF the blower switch and stop
the engine.
3. Disconnect the thermoswitch connector and check for con-
tinuity of the thermoswitch.
Terminals Continuity Action
a-b Yes Normal operation
No Redace thermoswitch
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TROUBLESHOOTING GUIDE
I I
Symptom: Insufficient cooling.
No cooling.
Intermittent cooling.
I I
03uoux-110
SIGHT GLASS
o5uoux-020
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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TROUBLESHOOTING GUIDE U
Measured press iure
_ow-side:
Below 78.5 kPa
(0.8 kg/cm’, 11.4 psi)
irgh-srde:
785 --883 kPa
(8-9 kg/cm’,
114-128 PSI)
-ow-srde:
Above 245 kPa
(2.5 kg/cm*, 35.6 psi)
iigh-srde:
Above 1,962 kPa
(20 kg/cm*, 284 PSI)
-ow-side:
Above 245 kPa
(2.5 kg/cm*, 35.6 PSI)
High-side:
Above 2,256 kPa
(23 kg/cm’, 327 psi)
Low-ade:
50 cmHg (2.0 inHg) of
Vacuum-l 47 kPa
(1.5 kg/cm2, 21.3 psi)
High-side:
687-i ,472 kPa
(7-15 kg/cm*,
loo-213 psi)
Low-side:
76 cmHg (3.0 inHg)
of Vacuum
High-side:
Below 589 kPa
(6 kg/cm’, 85 psi)
Low-side:
Above 245 kPa
(2.5 kg/cm’, 35.6 psi)
High-side:
1,864-l ,962 kPa
(19-20 kg/cm2,
270-284 psi)
-.
Low-side:
392-589 kPa
(4-6 kg/cm’,
57-85 psi)
High-side:
687-981 kPa
(7-10 kg/cm*,
100-I 42 psi)
T-
- Possible cause
nsufflcient refrigerant
!xcessive refrigerant or insuffi-
:ient condenser cooling
Air in system
Moisture in system
No refrigerant circulation
Expansion valve stuck open
Faulty compressor Action
Case 1
(Refer to page U-16)
Case 2
(Refer to page U-17)
Case 3
(Refer to page U-17)
Case 4
(Refer to page U-18)
Case 5
(Refer to page U-18)
Case 6
(Refer to page U-19)
Case 7
(Refer to page U-19)
03uoux-0:
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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.
U-16

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
13uoux-00 5 03uoux-031
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
I
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.)
SMUOUX-088
CAUSE ACTION
7 r
MOISTURE
IN SYSTEM WW;MTE
-
23uoux-O!
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
I I
05UOUX-02
CAUSE ACTION
23UOUX-OE
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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TROUBLESHOOTING GUIDE U
Case 6 Expansion valve stuck open
Measured pressure
Low-pressure: Above 245 kPa (2.5 kg/cm2, 35.6 psi)
High-pressure: 1,864-l ,962 kPa (19-20 kg/cm2, 270-284 psi)
Condition
Insufficient cooling
QMUOUX-093
23UOUX-01’
1. Check whether there is frost or heavy dew on the suction
pipe (between cooling unit and compressor).
2. If neither is found, refer to “Excessive refrigerant or insuffi-
cient condenser cooling”; page U-17.
3. If either is found, replace the expansion valve.
(Refer to page U-39.)
Case 7 Faulty compressor
Measured pressure
Low-pressure: 392-589 kPa (4-6 kg/cm2, 57-85 psi)
High-pressure: 687-981 kPa (7-10 kg/cm2, loo-142 psi)
Condition
No cooling
MOISTURE EVACUATE
IN SYSTEM SYSTEM
I
9MUOUX-095
1. Run the engine at a fast idle.
2. Verify that the magnetic clutch is ON when the A/C switch
and blower switch are ON.
3. If the magnetic clutch remains OFF, refer to “Magnetic
clutch does not operate”; page U-10.
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U HEATER
HEATER
STRUCTURAL VIEW
1, Heater unit 3. Heater control unit
Removal / Installation.. page U-21 Removal / Installation.. ................ page U-26
................
Disassembly I Assembly.. ........... page U-22 Disassembly I Assembly.. ........... page U-27
2. Blower unit inspection ................................... page U-28
Removal I Installation.. page U-23 Adjustment ................................. page U-28
................
Disassembly / Assembly ............. page U-24
Inspection
................................... page U-25
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