B1421

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): B1421/21: Solar Sensor Circuit (Passenger Side)
B1421/21 - Solar Sensor Circuit (Passenger Side)

DESCRIPTION

The solar sensor, which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning AUTO mode. The output voltage from the solar sensor varies in accordance with the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases.

The air conditioning amplifier detects changes in the output voltage from the solar sensor.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream ON.

(c) Select the item below in the Data List, and read the value displayed on the Techstream.

Air conditioning amplifier:





OK:

The display is as specified in the normal condition column.

Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER

B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.

2. INSPECT COOLER (SOLAR SENSOR) THERMISTOR

(a) Remove the solar sensor.





(b) Measure the resistance of the sensor.

(c) Connect the ohmmeter's positive (+) lead to terminal 1 and the negative (-) lead to terminal 2 of the solar sensor.

Standard resistance:





NOTICE:
The connection procedure for using a digital tester such as an electrical tester is shown above. When using an analog tester, connect the positive (+) lead to terminal 2 and the negative (-) lead to terminal 1 of the solar sensor.

HINT
- As the inspection light is moved away from the sensor, the voltage decreases.
- Use an incandescent light for the inspection. Position it about 30 cm (11.8 in.) from the solar sensor.

NG -- REPLACE COOLER (SOLAR SENSOR) THERMISTOR
OK -- Continue to next step.

3. CHECK WIRE HARNESS (SOLAR SENSOR - AIR CONDITIONING AMPLIFIER)

(a) Disconnect the F1 sensor connector.





(b) Disconnect the E37 amplifier connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR

OK -- REPLACE AIR CONDITIONING AMPLIFIER