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Home >> Toyota >> 1987 >> Celica L4-2.0L (3S-FE) >> Repair and Diagnosis >> Heating and Air Conditioning >> Control Assembly >> Testing and Inspection
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Control Assembly: Testing and Inspection





1. Measure temperature control lever resistance. Measure the resistance between terminals A13 and A14 for each lever position.

Lever position Resistance (k Ohms)
Max. Cool Infinity
Middle 1.5 +/- 0.2
Max. Warm 0
If each resistance value is not as shown in the table above, replace the heater control assembly.





2. Inspect indicator light operation.
a. Connect the positive (+) battery lead to terminal A7 and the negative (-) battery lead to terminal A3.
b. With the blower button pushed in, check that the indicator light is lit. (The indicator light will not go on when the blower button is in the OFF position.)
c. With the RECIRC/FRESH control button pushed in, check that the (RECIRC) indicator light is lit.
d. Next, press the RECIRC/FRESH control button in again (FRESH) and check that the indicator light goes off.
e. Press each of the mode buttons in and check that their indicator lights go on.
If operation is not as specified, replace the heater control.





3. Inspect illumination operation. Check that the illumination lights come on when the positive (+) battery lead is connected to terminal A4, and the negative (-) battery lead is connected to terminal A5.
If operation is not as specified, inspect the bulbs.









4. Inspect blower switch continuity between terminals.
If continuity is not as specified, replace the heater control.









5. Inspect the mode switch continuity between terminals.
If continuity is not as specified, replace the heater control.





6. Inspect RECIRC/FRESH control switch operation. With the positive (+) battery lead connected to terminal A7, and the negative (-) battery lead connected to terminal All, check that the RECIRC indicator light comes on.
If operation is not as specified, replace the heater control.


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