Rear A/C Control Assembly: Inspection

Using a screwdriver, release the 4 claws and pull out the rear heater control assembly, then disconnect the connector.

Fig 1: Removing Rear Heater Control Assembly

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Connect the positive (+) lead to terminal 2 and negative (-) lead to terminal 21 then check that the indicators come on.

If operation is not as specified, replace the rear A/C control assembly.

Fig 2: Inspecting Indicator Illumination Operation

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1. Connect the positive (+) lead all the other terminals to terminal 1 and negative (-) lead to, then check that the indicator comes on, as shown in the chart.
   INDICATOR SWITCH - TESTER CONNECTION
   
   

   Switch	Tester connection
   Auto	3
   LO	4
   ME	5
   HI	6
   FACE	7
   Bi-Level	8
   FOOT	9

   Fig 3: Inspecting Indicator Operation (1 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   If operation is not as specified, replace the rear A/C control assembly.

2. Connect the positive (+) lead from the battery to terminal 2, then check whether the indicators dim.
   Fig 4: Inspecting Indicator Operation (2 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   If operation is not as specified, replace the rear A/C control assembly.

Check the continuity between terminals while switch is pressed, as shown in the chart.

Fig 5: Inspecting Switch Continuity

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If continuity is not as specified, replace the rear A/C control assembly.

1. Measure resistance between terminal 10 and 12.

   Standard resistance: 3.0 kΩ 

2. Gradually move the temperature control lever from "COOL" side to "WARM" side, then check that the resistance between terminal 11 and 12 increase to 3.0 kΩ.
   Fig 6: Inspecting Variable Resistor Operation

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If operation is not as specified, replace the rear A/C control assembly.