Subaru Legacy 2002 Service Manual page 3192

DIAGNOSTICS FOR A/C SYSTEM FAILURE (RHD MODEL)
No.
1 CHECK FUSE.
1) Turn ignition switch to OFF.
2) Remove No. 2 and No. 17 fuses in joint
box.
3) Check condition of each fuse.
2 CHECK POWER SUPPLY TO BLOWER FAN
MOTOR.
1) Turn ignition switch to ON.
2) Turn blower switch to ON (Hi).
3) Measure voltage between blower fan motor
and chassis ground.
Connector & terminal
(B) No. 1 (+) — Chassis ground (−):
3 CHECK VOLTAGE BETWEEN BLOWER
FAN MOTOR AND CHASSIS GROUND.
Measure voltage between blower fan motor
connector and chassis ground.
Connector & terminal
(B) No. 2 (+) — Chassis ground (−):
4 CHECK RESISTANCE BETWEEN BLOWER
FAN MOTOR AND CHASSIS GROUND.
Measure resistance between blower fan motor
connector and chassis ground.
Connector & terminal
(B) No. 3 — Chassis ground:
5 CHECK A/C CONTROL MODULE.
Measure voltage between A/C control module
connector and chassis ground.
Connector & terminal
(i49) No. 5 (+) — Chassis ground (−):
6 CHECK A/C CONTROL MODULE.
Measure voltage between A/C control module
connector and chassis ground.
Connector & terminal
(i49) No. 3 (+) — Chassis ground (−):
7 CHECK BLOWER FAN MOTOR RELAY.
1) Turn ignition switch to OFF.
2) Remove blower fan motor relay.
3) Connect battery to No. 1 and No. 3 termi-
nals of blower fan motor connector.
4) Measure resistance between No. 2 and No.
4 terminals.
Terminals:
No. 2 — No. 4
8 CHECK POOR CONTACT.
Check poor contact in A/C control module.
Step
Are any of the fuses blown-
out?
Is the voltage more than 10
V?
Is the voltage approxi-
mately 0 V?
Is the resistance less than
1 Ω?
Is the voltage approxi-
mately 0 V?
Is the voltage approxi-
mately 0 V?
Is the resistance less than
1 Ω?
Is there poor contact in A/C
control module?
AC-49
HVAC System (Auto A/C) (Diagnostics)
Check Yes
Replace fuse.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Go to step 7.
Go to step 8.
Repair poor con-
tact in A/C control
module.
No
Go to step 2.
Go to step 7.
Replace blower
fan motor. <Ref.
to AC-30, Blower
Motor Assembly.>
Replace blower
fan motor. <Ref.
to AC-30, Blower
Motor Assembly.>
Replace A/C con-
trol module.
Replace A/C con-
trol module.
Replace blower
fan motor relay.
Repair open cir-
cuit in harness for
blower fan motor.