Automatic Air Conditioning

AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): B1422/22: Compressor Lock Sensor Circuit
B1422/22 - Compressor Lock Sensor Circuit

DESCRIPTION

This sensor sends 1 pulse per engine revolution to the air conditioning amplifier. If the ratio of the compressor speed divided by the engine speed is smaller than a predetermined value, the air conditioning amplifier turns the compressor off, and the indicator blinks at approximately 1 second intervals.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK AIR CONDITIONING AMPLIFIER (LOCK SIGNAL)





(a) Remove the air conditioning amplifier with its connectors still connected.

(b) Check the waveform of the amplifier connector.

OK:

Waveform is as shown in the illustration.





Result:





C -- REPLACE AIR CONDITIONING AMPLIFIER

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

2. INSPECT COMPRESSOR LOCK SENSOR





(a) Disconnect the B47 compressor lock sensor connector.

(b) Measure the resistance of the sensor.

Standard resistance:





NG -- REPLACE COMPRESSOR LOCK SENSOR
OK -- Continue to next step.

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





(a) Disconnect the B47 compressor lock 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