RADIATOR MAIN FAN SYSTEM
Cooling
2. Radiator Main Fan System
S176732
A: SCHEMATIC
S176732A21
for_01_15-9.jpg
S2M2148
CO-8
RADIATOR MAIN FAN SYSTEM
Cooling
-  Vehicle speed is below 19 km/h (12 MPH). TROUBLE SYMPTOM:
-   Radiator main fan does not rotate under the above conditions.
B: INSPECTION
S176732A10
DETECTING CONDITION:
Condition:
- Engine coolant temperature is above 95°C (203° F).
No.
Step
Check
Yes
No
1
CHECK POWER SUPPLY TO MAIN FAN MOTOR. CAUTION: Be careful not to overheat engine during repair. 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 (-):
Is the voltage more than 10 V?
Go to step 2.
Go to step 5.
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 resistance less than 5Q?
Go to step 3.
Repair open cir­cuit in harness between main fan motor connector and chassis ground.
3
CHECK POOR CONTACT.
Check poor contact in main fan motor con­nector.
Is there poor contact in main fan motor connector?
Repair poor con­tact in main fan motor connector.
Go to step 4.
4
CHECK MAIN FAN MOTOR.
Connect battery positive (+) terminal to termi­nal No. 2, and negative (-) terminal to termi­nal No. 1 of main fan motor connector.
Does the main fan rotate?
Repair poor con­tact in main fan motor connector.
Replace main fan motor with a new one.
5
CHECK POWER SUPPLY TO MAIN FAN RELAY.
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. 26 (+) - Chassis ground (-):
Is the voltage more than 10 V?
Go to step 6.
Go to step 7.
6
CHECK POWER SUPPLY TO MAIN FAN RELAY.
1) Turn ignition switch to ON. 2) Measure voltage between main fan relay terminal and chassis ground. Connector & terminal (F66) No. 28 (+) - Chassis ground (-):
Is the voltage more than 10 V?
Go to step 10.
Go to step 9.
7
CHECK 20 A FUSE.
1) Remove 20 A fuse from A/C relay holder. 2) Check condition of fuse.
Is the fuse blown-out?
Replace fuse.
Go to step 8.
CO-9
RADIATOR MAIN FAN SYSTEM
Cooling
No.
Step
Check
Yes
No
8
CHECK POWER SUPPLY TO A/C RELAY
Is the voltage more than 10
Repair open cir-
Repair open cir-
HOLDER 20 A FUSE TERMINAL.
V?
cuit in harness
cuit in harness
Measure voltage of harness between A/C
between 20 A
between main
relay holder 20 A fuse terminal and chassis
fuse and main fan
fuse box connec-
ground.
relay terminal.
tor and 20 A fuse
Connector & terminal
terminal.
(F27) No. 1 (+) - Chassis ground (-):
9
CHECK FUSE.
Is the fuse blown-out?
Replace fuse.
Repair open cir-
1) Turn ignition switch to OFF.
cuit in harness
2) Remove fuse No. 18 from joint box.
between main fan
3) Check condition of fuse.
relay and ignition
switch.
10
CHECK MAIN FAN RELAY.
Is the resistance more than
Go to step 11.
Replace main fan
1) Turn ignition switch to OFF.
1 MQ?
relay.
2) Remove main fan relay.
3) Measure resistance of main fan relay.
Terminal
No. 26 - No. 25:
11
CHECK MAIN FAN RELAY.
Is the resistance less than
Go to step 12.
Replace main fan
1) Connect battery to terminals No. 27 and
1 Q?
relay.
No. 28 of main fan relay.
2) Measure resistance of main fan relay.
Terminal
No. 26 - No. 25:
12
CHECK HARNESS BETWEEN MAIN FAN
Is the resistance less than
Go to step 13.
Repair open cir-
RELAY TERMINAL AND MAIN FAN MOTOR
1 Q?
cuit in harness
CONNECTOR.
between main fan
Measure resistance of harness between main
motor connector
fan motor connector and main fan relay termi-
and main fan
nal.
relay terminal.
Connector & terminal
(F17) No. 2 - (F66) No. 25:
13
CHECK HARNESS BETWEEN MAIN FAN
Is the resistance less than
Go to step 14.
Repair open cir-
RELAY AND ECM.
1 Q?
cuit in harness
1) Turn ignition switch to OFF.
between main fan
2) Disconnect connector from ECM.
relay and ECM.
3) Measure resistance of harness between
main fan relay connector and ECM connector.
Connector & terminal
(F66) No. 27 - (B134) No. 3 (SOHC
MODEL):
(F66) No. 27 - (B84) No. 2 (SOHC w/o
OBD MODEL):
(F66) No. 27 - (B137) No. 17 (DOHC
TURBO MODEL):
14
CHECK POOR CONTACT.
Is there poor contact in
Repair poor con-
Contact your
Check poor contact in connector between
connector between main
tact connector.
Subaru distributor.
main fan and ECM.
fan motor and ECM?
NOTE:
Inspection by your Subaru distributor is required,
because probable cause is deterioration of multiple
parts.
CO-10