Heater & Air Conditioner: Overview Toyota Highlander I

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1. DO NOT HANDLE REFRIGERANT IN AN ENCLOSED AREA OR NEAR AN OPEN FLAME
2. ALWAYS WEAR EYE PROTECTION
3. BE CAREFUL NOT TO GET LIQUID REFRIGERANT IN YOUR EYES OR ON YOUR SKIN If liquid refrigerant gets in your eyes or on your skin: Wash the area with lots of cool water. CAUTION: Do not rub your eyes or skin. Apply clean petroleum jelly to the skin. Go immediately to a physician or hospital for professional treatment.
4. NEVER HEAT CONTAINER OR EXPOSE IT TO OPEN FLAME
5. BE CAREFUL NOT TO DROP CONTAINER AND NOT TO APPLY PHYSICAL SHOCKS TO IT
6. DO NOT OPERATE COMPRESSOR WITHOUT ENOUGH REFRIGERANT IN REFRIGERANT SYSTEM If there is not enough refrigerant in the refrigerant system, oil lubrication will be insufficient and compressor burnout may occur, so take care to avoid this, necessary care should be taken.
7. DO NOT OPEN HIGH PRESSURE MANIFOLD VALVE WHILE COMPRESSOR IS OPERATING If the high pressure valves opened, refrigerant flows in the reverse direction and could cause the charging cylinder to rupture, so open and close the only low pressure valve.
8. BE CAREFUL NOT TO OVERCHARGE SYSTEM WITH REFRIGERANT If refrigerant is overcharged, it causes problems such as insufficient cooling, poor fuel economy, engine overheating etc.

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1. INSPECT PRESSURE SWITCH NO. 1. Magnetic clutch control: Inspect pressure switch operation. Set on the manifold gauge set. Connect the positive (+) lead from the ohmmeter to terminal 4 and the negative (-) lead to terminal 1. Check continuity between terminals when refrigerant pressure is changed (Scheme 86)If operation is not as specified, replace the pressure switch. Cooling fan control: Inspect pressure switch operation. Connect the positive (+) lead from the ohmmeter to terminal 2 and the negative (-) lead to terminal 3. Check continuity between terminals when refrigerant pressure is changed (Scheme 87) If operation is not as specified, replace the pressure switch.
2. INSPECT AIR CONDITIONER AMPLIFIER ASSY CIRCUIT Disconnect the connectors from the A/C amplifier assy and inspect the connector on the wire harness side, as shown in «TESTER CONNECTION AND SPECIFIED CONDITION»(ref-191028-S40950184492005092000000). TESTER CONNECTION AND SPECIFIED CONDITION Tester Connection Condition Specified Condition A11 - Ground Constant Continuity B5 - B12 Evaporator Temp.: 25° C (77° F) 1.5kohms A2 - Ground Turn Ignition Switch: ON Battery Positive Voltage A2 - Ground Turn Ignition Switch: LOCK Or ACC No Voltage A12 - Ground Constant Battery Positive Voltage A13 - Ground Turn Ignition Switch: ACC Battery Positive Voltage A13 - Ground Turn Ignition Switch: Except ACC No Voltage If the circuit is as specified, try to replace the A/C amplifier assy with a new one. If the circuit is as specified, inspect the circuits connected to other parts. Connect the connector to A/C amplifier assy and inspect the wire harness side connector from the back side (Scheme 90) If the circuit is as specified, try to replace the A/C amplifier assy with a new one. If the circuit is as specified, inspect the circuits connected to other parts.

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1. COOLER THERMISTOR NO. 1 (MANUAL AIR CONDITIONER) Check resistance between terminals 1 and 2 of cooler thermistor No. 1 at each temperature (Scheme 92) Resistance: If resistance value is not as specified, replace the sensor.
2. HEATER BLOWER SWITCH (MANUAL AIR CONDITIONER) Inspect blower switch continuity. HEATER BLOWER SWITCH CONTINUITY Condition/Circuit Tester Connection Specified Condition OFF..... No Continuity LO 1-8 Continuity M1 1-6-8 Continuity M2 1-5-8 Continuity HI 1-4-8 Continuity If continuity is not as specified, replace the air conditioner control assy. Inspect illumination operation. Connect the positive (+) lead from the battery to terminal 2 and negative (-) lead to terminal 3 then check that the illuminations light up. If there is bulb not light up, replace the bulb.
3. BLOWER RESISTOR (MANUAL AIR CONDITIONER) Measure resistance between terminals (Scheme 94) BLOWER RESISTOR TERMINALS SPECIFICATIONS Tester Connection Specified Condition 1-2 0.642-0.738 ohms 1-3 0.205-0.235 ohms 1-4 1.572-1.803 ohms If resistance is not as specified, replace the blower resistor.
4. COOLING UNIT MOTOR SUB-ASSY W/FAN (MANUAL AIR CONDITIONER) Connect the positive (+) lead from the battery to terminal 2 and negative (-) to terminal 1, then check that the motor operation smoothly. If operation is not as specified, replace the blower motor.
5. HEATER BLOWER MOTOR RELAY ASSY (MANUAL AIR CONDITIONER) Check that the continuity exists between each pair of terminals of heater blower motor relay assy (Scheme 96) HEATER BLOWER MOTOR RELAY SPECIFICATIONS (1 OF 2) Tester Connection Specified Condition 1-4 No Continuity 2-4 Continuity 3-5 62.5-90.9ohms Apply battery voltage between terminals 3 and 5. Check continuity each pair of terminals (Scheme 96) HEATER BLOWER MOTOR RELAY SPECIFICATIONS (2 OF 2) Tester Connection Specified Condition 1-2 Continuity 2-4 No Continuity If continuity is not as specified, replace the heater blower motor relay.
6. MAGNET CLUTCH ASSY (MANUAL AIR CONDITIONER) Connect the positive (+) lead from the battery to terminal and the negative (-) lead to the body ground. Check that the magnetic clutch energized. If operation is not as specified, replace the magnet clutch assy.
7. COOLER COMPRESSOR ASSY (MANUAL AIR CONDITIONER) Disconnect the cooler compressor assy connector. Measure resistance between terminals 1 and 2 of cooler compressor assy connector. Resistance: 165-205 ohms at 20° C (68° F) If resistance is not as specified, replace the cooler compressor assy.
8. MAGNET-CLUTCH RELAY (MANUAL AIR CONDITIONER) If continuity is not as specified, replace the magnet-clutch relay.

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1. INSPECT REFRIGERANT VOLUME Observe the sight glass on the liquid tube. Test conditions: Running engine at 1,500 rpm Blower speed control switch at "HI" A/C switch ON Temperature control dial at "MAX. COOL" Fully open the doors
2. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET This is a method in witch the trouble is located by using a manifold gauge set. Read the manifold gauge pressure when the these conditions are established. Test conditions: Temperature at the air inlet with the switch set at RECIRC is 30-35° C (86-95° F) Engine running at 1, 500 rpm Blower speed control switch at HI position Temperature control dial at COOL position A/C switch ON Fully open doors Normally functioning refrigeration system. Gauge reading: Low pressure side: 0.15-0.25 MPa (1.5-2.5 kgf/cm 2 ) High pressure side: 1.37-1.57 MPa (14-16 kgf/cm 2 ) Moisture present in refrigeration system. Insufficient cooling Poor circulation of refrigerant Refrigerant does not circulate Refrigerant overcharged or insufficient cooling of condenser Air present in refrigeration system Expansion valve functions improperly Defective compression compressor

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1. DRAIN HFC-134A (R134A) Turn the A/C switch ON. Operating the cooler compressor at the engine rpm of approx. 1, 000 for 5 to 6 min., circulate the refrigerant and collect compressor oil remaining in each component into the cooler compressor as much as possible. Stop the engine. Let the refrigerant gas out. SST 07110-58060 (07117-58080, 07117-58090, 07117-78050, 07117-88060, 07117-88070, 07117-88080)
2. CHARGE REFRIGERANT Using a vacuum pump, perform a vacuum purging. Supply refrigerant, HFC-134a (R134a). Standard: 650 +/- 50 g (22.93 +/- 1.76 oz.) SST 07110-58060 (07117-58060, 07117-58070, 07117-58080, 07117-58090, 07117-78050, 07117-88060, 07117-88070, 07117-88080), 07117-48130, 07117-48140
3. WARM UP ENGINE
4. INSPECT LEAKAGE OF REFRIGERANT

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1. REMOVE V BELT (COOLER COMPRESSOR TO CRANKSHAFT PULLEY) NO. 1 Loosen the bolt C. Loosen the bolt A. Loosen the bolt B and remove the cooler V belt No. 1.
2. INSTALL V BELT (COOLER COMPRESSOR TO CRANKSHAFT PULLEY) NO. 1 Temporarily install the cooler V belt No. 1 as illustrated in (Scheme 132).
3. ADJUST V (COOLER COMPRESSOR TO CRANKSHAFT PULLEY) BELT NO. 1 Belt tension: 165 +/- 27 lbf for new belt 88 +/- 22 lbf for used belt
4. FULLY TIGHTEN V (COOLER COMPRESSOR TO CRANKSHAFT PULLEY) BELT NO. 1 Tighten the bolt A. Torque: 17.5 N.m (178 kgf.cm, 12 ft.lbf) Tighten the bolt C. Torque: 58 N.m (591 kgf.cm, 43 ft.lbf)