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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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 INDICATOR SWITCH - TESTER CONNECTION  .
   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.

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

Fig 4: Inspecting Indicator Operation (2 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

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.

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