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AIRCONDITIONING
C. TROUBLESHOOTINGON COOLER ELECTRICAL CIRCUIT
1. Troubleshooting Flow Chart
After making sure that the blower circuit operation is good, troubleshoot the cooler circuit in the following
procedures.
STEP 1 CHECK A/C SWITCH FUNCTION
STEP 2 CHECK MAGNETIC CLUTCH
STEP 3 CHECK POWER SOURCE TO CLUTCH
STEP 4 CHECK MAGNETIC CLUTCH RELAY
STEP 5 CHECK OUTPUT FROM AMPLIFIER
STEP 6 CHECK INPUT TO AMPLIFIER
With blower operated, push on
A/C switch, and check whether
A/C switch lamp is lit.
No
With A/C switch and blower
switches On, check whether
magnetic clutch is On.
Yes
Check voltage of 1-pole connec-
tor for the magnetic clutch.
Check voltages to clutch relay
Connector
No Battery Voltage
or No Grounding
Check output voltage from
amplifier.
Terminal 1A – OK
No Good
Inspect
A/C fuse
OK
Blown or
Bad Contact
Check wiring between
A/C fuse and the blower
circuit.
Check magnetic clutch
coil.
Step 4-1
Check relay and its wiring
Check continuity of wiring
between amplifier and mag-
netic clutch relay.
Check input
voltage to
A/C fuse
12V
Replace it
Check
A/C
switch
Check condenser
Fan relay circuit
12V
OK
OK
OK
Check each input voltage and sig-
nal from sensor such as Ther-
mistor, Dual Pressure S/W Engine RPM
signal from eng. ECU. Also
check the earth circuit for amplifier.
OK
Replace amplifier
Check sensor and its wiring,
which don't input correct sig-
nal.
Important
Also A/C idle up check should be done Visu-
allsy regardless of above troubleshooting result,
No
No Good
OK




