Heater Control Assembly: Inspection

WARNING: This page is about a different car, the 2002 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

Inspect Illumination Operation
Connect the positive (+) lead from the battery to terminal 8 and negative (-) lead to terminal 10 then check that the illuminations lights up.

Fig 1: Inspecting Illumination Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If operation is not as specified, check the faulty bulb.
Inspect Bulb
Using an ohmmeter, apply the tester as shown in Fig 2 to test for continuity.

Fig 2: Inspecting Bulb
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If continuity exists, replace the heater control.

If no continuity exists, replace the bulb.
Inspect A/C Indicator Operation
1. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminals 4 and 14.
  
  Fig 3: Inspecting A/C Indicator Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Push the A/C button in and then check that the indicator lights up.
  If operation is not as specified, replace the switch.
Inspect Dimming Operation
1. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminals 4 and 14 while pressing the switch.
  
  Fig 4: Inspecting Dimming Operation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the positive (+) lead from battery to terminal 8 and then check that the indicator dims.
  If operation is not as specified, replace the switch.
Inspect A/C Switch Continuity

Fig 5: Displaying A/C Switch & Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 6: Displaying A/C Continuity Based On Condition
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Switch continuity:
  If continuity is not as specified, replace the switch.
2. Illumination circuit:
  If continuity is not as specified, replace the bulb.
Inspect Blower Speed Control Switch Continuity

Fig 7: Display Blower Speed Control & Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 8: Displaying Blower Speed Continuity Based On Condition
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If continuity is not as specified, replace the switch.
Inspect Defroster Mode Switch Operation

Fig 9: Displaying Defroster Mode Switch & Circuit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 10: Displaying Defroster Mode Operation Based On Condition
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If no continuity exists, replace the switch.
Inspect Rear Defogger Switch Operation. See INSPECTION .
Inspect Security Indicator Light. See SECURITY INDICATOR LIGHT CIRCUIT .
Inspect Passenger Airbag Manual On-Off Indicator Operation. See PASSENGER-SIDE AIR BAG CUT-OFF SWITCH .