Back-Up Power Source Circuit

AIR CONDITIONING SYSTEM: Back-up Power Source Circuit

Back-up Power Source Circuit

DESCRIPTION

This is the back-up power source circuit for the A/C amplifier. Power is supplied even when turning the ignition switch off and is used for diagnostic trouble code memory, etc.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the fusible link block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE FUSE (ECU-B)
OK -- Continue to next step.
2. INSPECT AIR CONDITIONING AMPLIFIER





(a) Remove the A/C amplifier with the connectors still connected.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)





(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BODY GROUND)





(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER