Subaru LEGACY 2003 Service Manual page 9

B: INSPECTION
DETECTING CONDITION:
Condition:
• Engine coolant temperature is above 95°C (203°F).
• Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOM:
• Radiator main fan does not rotate under the above conditions.
1 CHECK POWER SUPPLY TO MAIN FAN MO-
TOR.
CAUTION:
Be careful not to overheat engine during re-
pair.
1) Turn ignition switch to OFF.
2) Disconnect connector from main fan motor.
3) Start the engine, and warm it up until
engine coolant temperature increases over
95°C (203°F).
4) Stop the engine and turn ignition switch to
ON.
5) Measure voltage between main fan motor
connector and chassis ground.
Connector & terminal
(F17) No. 2 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
2 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
(F17) No. 1 — Chassis ground:
Is the measured value less than the speci-
fied valve?
3 CHECK POOR CONTACT.
Check poor contact in main fan motor connec-
tor.
Is there poor contact in main fan motor con-
nector?
4 CHECK MAIN FAN MOTOR.
Connect battery positive (+) terminal to termi-
nal No. 2, and negative (−) terminal to terminal
No. 1 of main fan motor connector.
Does the main fan rotate?
5 CHECK POWER SUPPLY TO MAIN FAN RE-
LAY.
1) Turn ignition switch to OFF.
2) Remove main fan relay from A/C relay
holder.
3) Measure voltage between main fan relay
terminal and chassis ground.
Connector & terminal
(F66) No. 8 (+) — Chassis ground ( − − − − ):
Does the measured value exceed the spec-
ified value?
RADIATOR MAIN FAN SYSTEM
Step Value
10 V
5 Ω
There is poor contact.
The main fan rotates.
10 V
CO(H4SO)-7
Yes
Go to step 2. Go to step 5.
Go to step 3. Repair open circuit
in harness
between main fan
motor connector
and chassis
ground.
Repair poor con- Go to step 4.
tact in main fan
motor connector.
Repair poor con- Replace main fan
tact in main fan motor with a new
motor connector. one.
Go to step 6. Go to step 7.
COOLING
No