IG Power Source Circuit

AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): IG Power Source Circuit

IG Power Source Circuit

DESCRIPTION

This is the main power source supplied to the A/C amplifier when the ignition switch is turned to the ON position. The power source supplied is used for operating the A/C amplifier and servomotor, etc.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.

If the engine still does not start, see the SFI system (Symptom Related Diagnostic Procedures) for 2AZ-FE, (Symptom Related Diagnostic Procedures) for 3MZ-FE).

PROCEDURE

1. INSPECT FUSE (HTR)
(a) Remove the HTR fuse from the driver side J/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPLACE FUSE
OK -- Continue to next step.
2. INSPECT AIR CONDITIONING AMPLIFIER (IG+ - BODY GROUND)





(a) Remove the A/C amplifier assembly with the connectors still connected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





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





(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