HVAC System: Diagnosis Mazda RX-8 I

REFRIGERANT SYSTEM PERFORMANCE TEST

1. Inspect the refrigerant pressure. (See «REFRIGERANT PRESSURE CHECK»(ref-178308-S02294065702005061400000) .)
2. Place a dry-bulb thermometer in the driver-side center ventilator outlet.
3. Start the engine and after it is warmed up, run it at a constant 1,500 rpm.
4. Set the fan switch to 4th speed.
5. Turn the A/C switch on.
6. Set to RECIRCULATE mode.
7. Set the temperature control to MAX COLD.
8. Set to VENT mode.
9. Close all the doors and windows.
10. Wait until the air conditioner output temperature stabilizes. Stabilized condition The A/C compressor repeatedly turns on and off at regular intervals.
11. After the blower air is stabilized, read the dry-bulb thermometer.
12. Verify the ambient temperature.
13. Verify that the temperature reading is in the shaded zone. If the there is any malfunction, inspect the refrigerant system according to the troubleshooting chart.

Scheme 2

Scheme 3

1. Connect the manifold gauge.
2. Start the engine and after it is warmed up, run it at a constant 1,500 rpm.
3. Set the fan switch to 4th speed.
4. Turn the A/C switch on.
5. Set to RECIRCULATE mode.
6. Set the temperature control to MAX COLD.
7. Set to VENT mode.
8. Close all the doors and all the windows.
9. Measure the manifold gauge reading and ambient temperature.
10. Verify that the high and low pressure readings are within each shaded zone. If there is any malfunction, inspect the refrigerant system according to the troubleshooting chart.

AIR FILTER INSPECTION

1. Verify that there is no damage, excessive dirt or abnormal odor on the air filter. If there is any malfunction, replace the air filter. NOTE: The air filter is replaced once a year or every 20,000 km {12,500 miles}. The air filter cannot be reused by cleaning it with water or compressed air.

Scheme 4

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See «REFRIGERANT CHARGING»(ref-178308-S32782399292005061400000) .)
3. Drain the engine coolant. (See «ENGINE COOLANT REPLACEMENT»(ref-178321-S36202521982005061400000) .)
4. Remove the following parts: Ashtray Console (See «CONSOLE REMOVAL/INSTALLATION»(ref-178403-S38824949812005061500000) .) Glove compartment (See «GLOVE COMPARTMENT REMOVAL/INSTALLATION»(ref-178403-S18416452892005061500000) ). Side panel (See «SIDE PANEL REMOVAL/INSTALLATION»(ref-178403-S13157293282005061500000) .) Lower panel (See «LOWER PANEL REMOVAL/INSTALLATION»(ref-178403-S02200989262005061500000) .) Column cover (See «COLUMN COVER REMOVAL/INSTALLATION»(ref-178403-S19828048582005061500000) .) Steering shaft installation nuts (See «STEERING WHEEL & COLUMN REMOVAL/INSTALLATION»(ref-178305-S33200224622005061400000) .) A-pillar trim (See «A-PILLAR TRIM REMOVAL/INSTALLATION»(ref-178403-S21109983142005061500000) .) Dashboard (See «DASHBOARD REMOVAL/INSTALLATION»(ref-178403-S29776327272005061500000) .) CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise or other malfunction could occur. Always plug open fittings immediately after removing any refrigeration cycle parts.
5. Remove the A/C unit as shown in the figure.
6. Install in the reverse order of removal.
7. Perform the refrigerant system performance test. (See «REFRIGERANT SYSTEM PERFORMANCE TEST»(ref-178308-S09431512962005061400000) .)

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 5

1. Disconnect the negative battery cable.
2. Remove the A/C amplifier.
3. Remove the airflow mode link set.
4. Remove the airflow mode main link as shown in the figure.
5. Install in the reverse order of removal.

Scheme 6

Scheme 7

1. Remove the following parts: Front seat (See «FRONT SEAT REMOVAL/INSTALLATION»(ref-178399-S29131125412005061500000) ). Rear seat (See «REAR SEAT REMOVAL/INSTALLATION»(ref-178399-S03461608852005061500000).) Inner scuff plate (See «INNER SCUFF PLATE REMOVAL/INSTALLATION»(ref-178403-S10793838542005061500000).) Ashtray illumination bulb (See «ASHTRAY ILLUMINATION BULB REMOVAL/INSTALLATION»(ref-178404-S31638874392005061500000).) Console (See «CONSOLE REMOVAL/INSTALLATION»(ref-178403-S38824949812005061500000).) Front side trim (See «FRONT SIDE TRIM REMOVAL/INSTALLATION»(ref-178403-S30520831602005061500000).) Tire house trim (See «TIRE HOUSE TRIM REMOVAL/INSTALLATION»(ref-178403-S34208887982005061500000).) Seat belt rail (See «FRONT SEAT BELT REMOVAL/INSTALLATION»(ref-178417-S22461250002005061500000).) Floor covering (See «FLOOR COVERING REMOVAL/INSTALLATION»(ref-178403-S40157804322005061500000).)
2. Remove in the order indicated in (Scheme 6).
3. Install in the reverse order of removal.

Scheme 8

Scheme 9

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See «REFRIGERANT CHARGING»(ref-178308-S32782399292005061400000).)
3. Remove the fresh-air duct and air cleaner. (See «INTAKE-AIR SYSTEM REMOVAL/INSTALLATION»(ref-178322-S25288823672005061400000).)
4. Remove the drive belt. (See «DRIVE BELT REPLACEMENT»(ref-178318-S33371335752005061400000).)
5. Do not allow remaining compressor oil in the A/C compressor and pipes to spill, and remove in the order indicated in (Scheme 8). CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise or other malfunction could occur. Always plug open fittings immediately after removing any refrigeration cycle parts.
6. Install in the reverse order of removal.
7. Perform the refrigerant system performance test. (See «REFRIGERANT SYSTEM PERFORMANCE TEST»(ref-178308-S09431512962005061400000).)

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 10

1. Remove the battery.
2. Remove the fresh-air duct and air cleaner. (See «INTAKE-AIR SYSTEM REMOVAL/INSTALLATION»(ref-178322-S25288823672005061400000).)
3. Discharge the refrigerant from the system. (See «REFRIGERANT CHARGING»(ref-178308-S32782399292005061400000).)
4. Remove the front side marker light. (See «FRONT SIDE MARKER LIGHT REMOVAL/INSTALLATION»(ref-178404-S29368030062005061500000).)
5. Remove the front bumper. (See «FRONT BUMPER REMOVAL/INSTALLATION»(ref-178300-S00403827762005061400000).)
6. Remove the drive belt. (See «DRIVE BELT REPLACEMENT»(ref-178318-S33371335752005061400000).)
7. Do not allow remaining compressor oil in the piping and connecting parts to spill, and remove in the order indicated in (Scheme 10). CAUTION: If moisture or foreign material enters the refrigeration cycle, cooling ability will be lowered and abnormal noise or other malfunction could occur. Always plug open fittings immediately after removing any refrigeration cycle parts.
8. Install in the reverse order of removal.
9. Perform the refrigerant system performance test. (See «REFRIGERANT SYSTEM PERFORMANCE TEST»(ref-178308-S09431512962005061400000).)

Scheme 11

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

Scheme 12

Scheme 13

Scheme 14

1. Install the SST (49 N061 0A0) to the arrow side of the clamp.
2. Push the SST (49 N061 0A0) with your thumb until it snaps into the clamp. CAUTION: Excessive force to the SST (49 N061 0A0) may damage the clamp. Be careful not to press hard when inserting the SST (49 N061 0A0) into the clamp.
3. Raise the stopper, and pull the SST (49 N061 0A0) from the piping.
4. Remove the SST (49 N061 0A0) from the clamp. CAUTION: Be careful not to bend the SST (49 N061 0A0) needle when removing the clamp. If the SST (49 N061 0A0) needle is bent, the clamp can not be opened.

EVAPORATOR TEMPERATURE SENSOR INSPECTION

Note. Inspect the evaporator temperature sensor when it is installed to the A/C unit. Set the fan switch to 4th speed. Set the temperature control to MAX COLD. Set the air intake mode to RECIRCULATE. Turn the A/C switch off. Close all of the doors and roll up all the windows. Wait for 5 min. Disconnect the evaporator temperature sensor connector. Measure the temperature at the air intake. Measure the resistance between evaporator temperature sensor terminals. If the characteristics of the evaporator temperature sensor are not as shown in the graph, replace the evaporator temperature sensor.

Scheme 15

Scheme 16

1. Disconnect the negative battery cable.
2. Discharge the refrigerant from the system. (See «REFRIGERANT CHARGING»(ref-178308-S32782399292005061400000).)
3. Hold the piping block with pliers or a similar tool and loosen the refrigerant pressure switch using a wrench.
4. Remove in the order indicated in (Scheme 16).
5. Install in the reverse order of removal.

A/C AMPLIFIER INSPECTION

1. Turn the ignition switch to the ON position.
2. Connect the negative (-) lead of the tester to body ground.
3. By inserting the positive (+) lead of the tester into each A/C amplifier terminal, measure the voltage according to the terminal voltage table. See «TERMINAL VOLTAGE TABLE (REFERENCE)»(ref-178308-S21384659712005061400000) . 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 A/C amplifier.

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23