Subaru Legacy 2002 Service Manual page 3186

DIAGNOSTICS FOR A/C SYSTEM FAILURE (LHD MODEL)
No.
7 CHECK GROUND CIRCUIT OF MAIN FAN
MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between main fan
motor connector and chassis ground.
Connector & terminal
4 CYLINDER ENGINE MODEL
(F17) No. 1 — Chassis ground:
6 CYLINDER ENGINE MODEL
(F17) No. 4 — Chassis ground:
8 CHECK POOR CONTACT.
Check poor contact in main fan motor con-
nector.
9 CHECK MAIN FAN MOTOR.
4 CYLINDER ENGINE MODEL
Connect battery positive (+) terminal to termi-
nal No. 2, and negative (−) terminal to termi-
nal No. 1 of main fan motor connector.
6 CYLINDER ENGINE MODEL
Connect battery positive (+) terminal to termi-
nal No. 1, 2, 3, and negative (−) terminal to
terminal No. 4 of main fan motor connector.
10 CHECK OPERATION OF SUB FAN MOTOR.
Check operation of sub fan motor.
11 CHECK POWER SUPPLY TO SUB FAN
MOTOR.
CAUTION:
Be careful not to overheat engine during
repair.
1) Turn ignition switch to OFF.
2) Disconnect connector from sub fan motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
100°C (212°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure voltage between sub fan motor
connector and chassis ground.
Connector & terminal
4 CYLINDER ENGINE MODEL
(F16) No. 2 (+) — Chassis ground (−):
6 CYLINDER ENGINE MODEL
(F16) No. 1, 2, 3 (+) — Chassis ground
(−):
12 CHECK GROUND CIRCUIT OF SUB FAN
MOTOR.
1) Turn ignition switch to OFF.
2) Measure resistance between sub fan motor
connector and chassis ground.
Connector & terminal
4 CYLINDER ENGINE MODEL
(F16) No. 1 — Chassis ground:
6 CYLINDER ENGINE MODEL
(F16) No. 4 — Chassis ground:
13 CHECK POOR CONTACT.
Check poor contact in sub fan motor connec-
tor.
Step
Is the resistance less than
1 Ω?
Is there poor contact in
main fan motor connector?
Does the main fan rotate?
Does the radiator sub fan
operate?
Is the voltage more than 10
V?
Is the resistance less than
1 Ω?
Is there poor contact in sub
fan motor connector?
AC-43
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Go to step 8.
Repair poor con-
tact in main fan
motor connector.
Repair poor con-
tact in main fan
motor connector.
Go to step 15.
Go to step 12.
Go to step 13.
Repair poor con-
tact in sub fan
motor connector.
No
Repair open cir-
cuit in harness
between main fan
motor connector
and chassis
ground. <Ref. to
CO-7,
SCHEMATIC,
Radiator Main
Fan System.>
Go to step 9.
Replace main fan
motor with a new
one.
Go to step 11.
Repair open cir-
cuit in harness for
power supply cir-
cuit. <Ref. to
CO-10,
SCHEMATIC,
Radiator Sub Fan
System.>
Repair open cir-
cuit in harness
between sub fan
motor connector
and chassis
ground. <Ref. to
CO-10,
SCHEMATIC,
Radiator Sub Fan
System.>
Go to step 14.