Examination
1. Check backlight operation:
- A) Connect the battery to the terminals "A9" (+) And "A20" (-). Check that the backlight is on. If the lamp does not light, perform the following checks.
- b) Disconnect the air conditioning control panel from the amplifier. Connect the battery to the terminals "C15" (+) And "C1" (-).
If the lamp does not light, replace the lamp. If the lamp is on, check the connection between the air conditioner amplifier and the control panel or replace the amplifier.
2. Check the operation of the air intake damper switch.
- A) Connect the battery to the terminals "A1" (+) And "A20" (-). Check that the control lamp lights up each time the switch is pressed.
- b) Switch positive wire to terminal "A9", check that the lamp goes out.
If the job does not match the description, perform the following checks:
- A) Disconnect the air conditioning control panel from the amplifier. Connect the battery to the terminals "C14" (+) And "C1" (-). Check that the control lamp lights up each time the switch is pressed.
- V) Switch positive wire to terminal "C15", check that the lamp goes out. If the operation is not as described, replace the A/C control unit.
If the operation is as described, check the contact between the A/C amplifier and the control panel or replace the amplifier.
3. Check the operation of the air conditioner mode switch. The check is carried out similarly to paragraph 2.
4. Check the operation of the air conditioner switch.
- A) Connect the battery to the terminals "A1" (+) And "A20" (-). Check that the indicator lamp comes on when the air conditioner button is pressed and the heater fan switch is in the "ON".
- b) Switch positive wire to terminal "A9", check that the lamp goes out.
If the job does not match the description, perform the following checks.
- V) Disconnect the air conditioning control panel from the amplifier. Connect the battery to the terminals "C14" (+) And "C12" (-). Check that the lamp lights up when the air conditioner start button is pressed.
- G) Switch positive wire to terminal "C15", negative on "C1" and check that the lamp goes out.
- d) Switch positive wire to terminal "C14".
- e) Check that the voltage between the terminals "C13" (+) And "C1" (-) is approximately 12 V.
If the operation is not as described, replace the air conditioning control panel.
If the operation is as described, check the contact between the A/C amplifier and the control panel or replace the amplifier.
5. Check the operation of the heater fan speed controller.
- A) Disconnect the air conditioning control panel from the amplifier.
- b) Check that the resistance between the terminals "C1" And "C9" about 1.5 kOhm.
- V) Gradually move the lever from position "OFF" V "HI". Check that the resistance between the terminals "C1" And "C11" increases from 0 to 3 kΩ.
If the operation is not as described, replace the air conditioning control panel.
If the operation is as described, check the contact between the A/C amplifier and the control panel or replace the amplifier.
6. Check the operation of the temperature controller.
- A) Disconnect the air conditioning control panel from the amplifier.
- b) Check that the resistance between the terminals "C1" And "C9" about 1.5 kOhm.
- V) Gradually move the lever from position "OFF" V "HI" Check that the resistance between the terminals "C1" And "C10" increases from 0 to 3 kΩ.
If the operation is not as described, replace the A/C control assembly.
If the operation is as described, check the contact between the A/C amplifier and the control panel or replace the amplifier.
7. Check the A/C control circuit.
- A) Disconnect the A/C control panel from the amplifier and check the connector on the wire side as shown in Table 1.
Note: The test is carried out with the ignition on.
If the circuit matches the chart, replace the A/C amplifier. If the circuit does not match the chart, check other system components.
- b) Connect the connector to the A/C control box and check the connector from the rear as shown in Table 2.
Verification conditions
- The ignition is on.
- Fan speed control in position "HI".
- A/C switch in position "ON".
- Temperature regulator in position "MAX COOL".
If the target matches the table, replace the A/C amplifier. If the target does not match the table, check other elements of the system.