Air Conditioning System: Inspection

WARNING: This page is about a different car, the 2004 Scion xB. However, it is still accessible from the selected car via links, so may be relevant.

COOLER THERMISTOR NO. 1
1. Inspect cooler thermistor No. 1 continuity.
  1. Measure the resistance between terminals 1 and 2 of the cooler thermistor No. 1 at each temperature, as shown in the chart.
  Standard:
  
  Fig 1: Resistance And Temperature Relating Graph - Cooler Terminal No. 1
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Identifying Cooler Thermistor No. 1 Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If resistance value is not as specified, replace the cooler thermistor No. 1
THERMISTOR ASSY
1. Inspect thermistor assy continuity.
  1. Measure the resistance between terminals 1 and 2 of thermistor assy according to the value(s) in the table below.
    Standard:
    
    Fig 3: Resistance Specified Condition Table - Thermistor Assembly
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  Fig 4: Identifying Thermistor Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the value is not as specified, replace the thermistor assy.
CENTER CLUSTER MODULE SWITCH
1. Inspect blower switch continuity.
  1. Measure the resistance according to the value(s) in the table below.
    
    Fig 5: Resistance Specified Condition Table - Center Cluster Module Switch
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  Fig 6: Inspecting Illumination Operation And Connector View
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the value is not as specified, replace the center cluster module switch.
2. Inspect illumination operation.
  Connect the positive (+) lead from the battery to terminal 4 and negative (-) lead to terminal 5, then check that the illuminations come on.
  
  If there is any bulb which does not come on, replace the bulb.
3. Inspect switch continuity.
  Measure the resistance according to the value(s) in the table below.
  
  Standard:
  
  Fig 7: Resistance Specified Condition Table - Cooler Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If continuity is not as specified, replace the cooler switch.
4. Inspect indicator operation.
  1. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to terminal 1.
  2. Push the A/C button in and then check that the indicator comes on.
If operation is not as specified, replace the cooler switch.

Fig 8: Identifying Cooler Switch And Connector View
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
BLOWER RESISTOR
1. Inspect blower resistor continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 9: Resistance Specified Condition Table - Blower Resistor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 10: Identifying Blower Resister Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If the value is not as specified, replace the blower resistor.
BLOWER W/FAN MOTOR SUB-ASSY
1. Inspect blower w/fan motor SUB-ASSY.
  1. Connect the positive (+) lead from the battery to terminal 2 and negative (-) lead to terminal 1, then check that the motor operates smoothly.
If operation is not as specified, replace the blower motor.

Fig 11: Inspecting Blower W/Fan Motor Sub-Assembly
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DAMPER SERVO SUB-ASSY
1. Inspect damper servo SUB-ASSY.
  1. Connect the positive (+) lead from the battery to terminal 7 and the negative (-) lead to terminal 8.
  Standard:
  
  Fig 12: Damper Servo Sub-Assembly Operation Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If operation is not as specified, replace the damper servo SUB-ASSY.

Fig 13: Inspecting Damper Servo Sub-Assembly And Connector View
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
W/PULLEY COMPRESSOR ASSY
1. Inspect w/pulley compressor assy.
  1. Measure the resistance between terminals 1 and 2.
  Standard resistance: 160 to 320 Ω at 20°C (68°F)
If the value is not as specified, replace the w/pulley compressor assy.

Fig 14: Identifying A/C Compressor Clutch Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
COOLER WIRING NO. 2
1. Inspect foot, foot/def switch continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 15: Foot/Def Switch Connector Terminal Resistance Values Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 16: Identifying Foot/Def Switch Connector Terminal
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect MAX hot switch continuity.
  1. Using a service wire, connect connector A-1 and connector A-2 between the MAX hot switch and cooler wiring No. 2.
  2. Check that the continuity exists between terminals.
  Standard:
  
  Fig 17: MAX Hot Switch Operation Table - Cooler Wiring No. 2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 18: Identifying MAX Hot Switch Connector A And B Terminals - Cooler Wiring No. 2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HEATER SWITCH ASSY
1. Inspect heater switch assy continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 19: Specified Condition Table - Heater Switch Assembly
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 20: Identifying Heater Switch Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If continuity is not as specified, replace the heater switch assy.
MAX HOT SWITCH
1. Inspect MAX hot switch continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 21: Switch Operation And Specified Condition Table - MAX Hot Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 22: Identifying MAX Hot Switch Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If continuity is not as specified, replace the max hot switch.
HEATER BLOWER MOTOR RELAY ASSY
1. Inspect relay assy (for heater blower motor) continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 23: Specified Condition Table - Heater Blower Motor Relay Assembly
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 24: Inspecting Heater Blower Motor Relay Continuity And Terminal View
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the value is not as specified, replace the relay assy (for heater blower motor).
PTC HEATER RELAY
1. Inspect PTC heater relay continuity.
  1. Measure the resistance according to the value(s) in the table below.
  Standard:
  
  Fig 25: Resistance Specified Condition Table - PTC Heater Relay
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 26: Inspecting PTC Heater Relay Continuity And Connector Terminals View
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If the value is not as specified, replace the PTC heater relay.