HVAC System: Diagnosis Mazda 3 BK

EVAPORATOR INSPECTION

1. Inspect the evaporator for damage, cracks, and oil leakage. If there is any malfunction, replace the evaporator.
2. Visually inspect the fins for bending. If there is any bending, use the end of a flathead screwdriver to straighten the fins.

HEATER CORE INSPECTION

1. Inspect the heater core for damage, cracks, and water leakage. If there is any malfunction, replace the heater core.
2. Visually inspect the fins for bending. If there is any bending, use the end of a flathead screwdriver to straighten the fins.
3. Visually inspect the heater hose for deformation. Repair with pliers if there is deformation. If there is any malfunction, replace the heater core.

Scheme 2

1. Disconnect the negative battery cable.
2. Detach the hood release lever from the lower panel. See «HOOD LATCH AND RELEASE LEVER REMOVAL/INSTALLATION»(ref-177783-S33436475022005060700000) .
3. Remove the front scuff plate. See «FRONT SCUFF PLATE REMOVAL/INSTALLATION»(ref-177786-S35097446782005060700000) .
4. Remove the front side trim. See «FRONT SIDE TRIM REMOVAL/INSTALLATION»(ref-177786-S00759394172005060700000) .
5. Remove the lower panel. See «LOWER PANEL REMOVAL/INSTALLATION»(ref-177786-S23426726492005060700000) .
6. Remove the shower duct (LH).
7. Disconnect the airflow mode wire. See «CLIMATE CONTROL UNIT REMOVAL»(ref-177717-S02519958822005060400000) .
8. Remove the airflow mode rod (1).
9. Remove the airflow mode main link.
10. Install in the reverse order of removal.
11. Adjust the airflow mode wire. See «CLIMATE CONTROL UNIT WIRE ADJUSTMENT»(ref-177717-S26120315952005060400000) .

CONDENSER INSPECTION

1. Inspect the condenser for cracks, damage, and oil leakage. If there is any malfunction, replace the condenser.
2. Visually inspect the fins for clogging of foreign material. If any fins are clogged, remove the foreign material.
3. Visually inspect the fins for bending. If there is any bending, use the end of a flathead screwdriver to straighten fins.

Scheme 3

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. See «REFRIGERANT RECOVERY»(ref-177717-S29446860652005060400000) . See «REFRIGERANT CHARGING»(ref-177717-S21873137252005060400000) .
3. Remove the under cover. CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise will occur. Always immediately plug all open fitting after removing any refrigeration cycle parts to keep moisture or foreign material out of the cycle.
4. Remove the receiver/drier. Do not allow compressor oil to spill.
5. Install in the reverse order of removal.
6. Perform the refrigerant system performance test. See «REFRIGERANT SYSTEM PERFORMANCE TEST»(ref-177717-S02744042172005060400000) .

Scheme 4

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. See «REFRIGERANT RECOVERY»(ref-177717-S29446860652005060400000) . See «REFRIGERANT CHARGING»(ref-177717-S21873137252005060400000) .
3. Remove the P/S fluid reserve tank.
4. Remove the coolant reserve tank. See «COOLANT RESERVE TANK REMOVAL/INSTALLATION»(ref-177562-S24677662192005060200000) .
5. Remove the accelerator cable.
6. Remove the P/S fluid hose bracket.
7. Remove the under cover.
8. Remove in the order indicated in the figure. Do not allow compressor oil to spill. CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise will occur. Always immediately plug all open fittings after removing any refrigeration cycle parts to keep moisture or foreign material out of the cycle.
9. Install in the reverse order of removal.
10. Perform the refrigerant system performance test. See «REFRIGERANT SYSTEM PERFORMANCE TEST»(ref-177717-S02744042172005060400000) .

Scheme 5

1. Disconnect the block joint type pipes by grasping female side of the block with pliers or similar tool and holding firmly, then remove the connection bolt or nut.

Scheme 6

Scheme 7

Scheme 8

1. Set the SST.
2. While looking through the inspection hole of the SST , insert the protruding part of the SST until it makes contact with the cage section.
3. Use the SST to disconnect the male pipe or hose from the female by pulling the male pipe or hose. NOTE: The male pipe or hose can be disconnected easily from the female pipe by pulling from the male pipe or hose while maintaining the pressure of the protruding part of the SST.

BLOWER MOTOR INSPECTION

Connect battery positive voltage to blower motor terminal A, connect terminal B to ground, and then verify its operation.

Scheme 9

1. If there is any malfunction, replace the blower motor.

Scheme 10

1. Disconnect the negative battery cable.
2. Remove the two nuts securing the cooler hose (LO).
3. Remove the following parts: Front doors. See «FRONT DOOR REMOVAL/INSTALLATION»(ref-177731-S33616524532005060700000) . Console. See «CONSOLE REMOVAL/INSTALLATION»(ref-177786-S07028325542005060700000) . Shift lever component (MTX). See «AUTOMATIC TRANSAXLE SHIFT MECHANISM»(ref-177780) . Selector lever component (ATX). See «SELECTOR LEVER COMPONENT REMOVAL/INSTALLATION»(ref-177780-S22412863032005060700000) . Decoration panel. See «DECORATION PANEL REMOVAL/INSTALLATION»(ref-177786-S19547422042005060700000) . Front scuff plate. See «FRONT SCUFF PLATE REMOVAL/INSTALLATION»(ref-177786-S35097446782005060700000) . Front side trim. See «FRONT SIDE TRIM REMOVAL/INSTALLATION»(ref-177786-S00759394172005060700000) . Glove compartment. See «GLOVE COMPARTMENT REMOVAL/INSTALLATION»(ref-177786-S24941703152005060700000) . Shower ducts (LH, RH). See «A/C UNIT REMOVAL/INSTALLATION»(ref-177717-S02082714782005060400000) . PJB. See «FUSES & CIRCUIT BREAKERS»(ref-168531) . Car-navigation unit. See «CAR-NAVIGATION SYSTEM»(ref-216090-S22984884282006011700000) . Lower panel. See «LOWER PANEL REMOVAL/INSTALLATION»(ref-177786-S23426726492005060700000) . Column cover. See «DASHBOARD REMOVAL/INSTALLATION»(ref-177786-S15974741452005060700000) . Meter hood. See «METER HOOD REMOVAL/INSTALLATION»(ref-177786-S19560981712005060700000) . Instrument cluster. See «INSTRUMENT CLUSTER REMOVAL/INSTALLATION»(ref-177791-S05027788752005060700000) . Steering shaft. See «STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION»(ref-177673-S09492789832005060300000) . A-pillar trim. See «A-PILLAR TRIM REMOVAL/INSTALLATION»(ref-177786-S26159187132005060700000) . Center panel module. See «INTERIOR TRIM»(ref-177786) . LCD unit. See «LCD UNIT REMOVAL/INSTALLATION»(ref-177789-S17800697552005060700000) . Windshield wiper arm and blade. See «WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALATION»(ref-177788-S15152889862005060700000) . Cowl grille. See «COWL GRILLE REMOVAL/INSTALLATION»(ref-177785-S07663231852005060700000) . Cowl panel. See «COWL PANEL REMOVAL/INSTALLATION»(ref-177729-S13496067802005060700000) . Windshield wiper motor. See «WINDSHIELD WIPER MOTOR REMOVAL/INSTALLATION»(ref-177788-S00751509092005060700000) .
4. Disconnect the air mix wire from the air mix link and wire clamp.
5. Disconnect the airflow mode wire from the airflow mode main link and wire clamp.
6. Disconnect the following connectors: Blower motor connector Evaporator temperature sensor connector Air intake actuator connector
7. Remove the rear heat duct (1).
8. Remove the heater case. See «A/C UNIT REMOVAL/INSTALLATION»(ref-177717-S02082714782005060400000) .
9. Remove the dashboard. See «DASHBOARD REMOVAL/INSTALLATION»(ref-177786-S15974741452005060700000) .
10. Move the A/C unit to the right and remove the resistor. CAUTION: While moving the A/C unit, do not apply excessive force. Otherwise it will result in deformation of the refrigerant piping or refrigerant gas leakage.
11. Install in the reverse order of removal.

Scheme 11

Scheme 12

1. Verify that the resistance between the resistor terminals is as shown in the figure. If there is any malfunction, replace the resistor.

Scheme 13

Scheme 14

1. Disassemble in the order indicated in the figure.
2. Assemble in the reverse order of disassembly.
3. Adjust the magnetic clutch clearance. «MAGNETIC CLUTCH ADJUSTMENT»(ref-177717-S18109782432005060400000) .

Scheme 15

1. When removing or installing the bolt, hold the pressure plate in place as shown in the figure.
2. When installing a new A/C compressor body, replace the recommended bolt.

EVAPORATOR TEMPERATURE SENSOR INSPECTION

Note. Inspect the evaporator temperature sensor when it is installed to the A/C unit.

Scheme 16

1. Set the fan speed MAX HI.
2. Set the temperature control at MAX COLD.
3. Set the RECIRCULATE mode.
4. Turn the A/C switch off.
5. Close all doors and windows.
6. Wait for 5 min.
7. Disconnect the evaporator temperature sensor connector.
8. Measure the temperature at the blower inlet.
9. Measure the resistance between the evaporator temperature sensor terminals. If the resistance is not as shown in the graph, replace the evaporator temperature sensor.

Scheme 17

Scheme 18

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. See «REFRIGERANT RECOVERY»(ref-177717-S29446860652005060400000) . See «REFRIGERANT CHARGING»(ref-177717-S21873137252005060400000) .
3. Loosen the refrigerant pressure switch using two spanners.
4. Remove in the order indicated in the figure.
5. Install in the reverse order of removal.

CLIMATE CONTROL UNIT INSPECTION

1. Install the PJB.
2. Turn the ignition switch to the ON position.
3. Connect the negative (-) lead of the tester to body ground.
4. By inserting the positive (+) lead of the tester into each climate control unit terminal, measure the voltage according to the terminal voltage table. See «TERMINAL VOLTAGE TABLE (REFERENCE)»(ref-177717-S35919748882005060400000) . If there is any malfunction, inspect the parts under "Inspection item (s)". If the parts under "Inspection item (s)" are found to be normal, replace the climate control unit.

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

1. Remove the climate control unit.
2. Verify that the continuity between the fan switch terminals is as indicated in the figure. If there is any malfunction, replace the fan switch.

Scheme 24