Rear A/C Control Assembly: Inspection

WARNING: This page is about a different car, the 2005 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

REMOVE REAR HEATER CONTROL ASSEMBLY
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
INSPECT ILLUMINATION OPERATION
Connect battery positive (+) lead to terminal 2 and battery 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 Illumination Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT INDICATOR OPERATION

Connect battery positive (+) lead to terminal 1 and battery negative (-) lead to all the other terminals, then check that the indicator come on, as shown in Fig 3.

INDICATOR OPERATION

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

Fig 3: Connecting Battery To Terminal 1 & Other Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Connect the positive (+) lead from the battery to terminal 2, then check where the indicators dim.
If operation is not as specified, replace the rear A/C control assembly.

Fig 4: Connecting Battery To Terminal 2
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT SWITCH CONTINUITY

Check the continuity between terminals while switch is pressed, as shown in Fig 5.

SWITCH CONTINUITY

Switch	Tester connection	Specified condition
Auto	13 - 22	Continuity
OFF	14 - 22	Continuity
LO	15 - 22	Continuity
ME	16 - 22	Continuity
HI	17 - 22	Continuity
FACE	18 - 22	Continuity
Bi-Level	19 - 22	Continuity
FOOT	20 - 22	Continuity

Fig 5: Checking Continuity Between Terminals While Switch Is Pressed

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

INSPECT VARIABLE RESISTOR OPERATION
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.
Fig 6: Inspecting Variable Resistor Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSTALL HEATER CONTROL ASSEMBLY