DIAGNOSTIC PROCEDURE
SYMPTOM: Blower motor operation is malfunctioning under
Starting Fan Speed Control.
CHECK POWER SUPPLY FOR FAN
CONTROL AMP.
Disconnect fan control amp. harness con-
nector.
Do approx. 12 volts exist between fan
control amp. harness terminal No.
V3and
body ground?
Yes
cNo
CHECK POWER SUPPLY
FOR BLOWER MOTOR.
Disconnect blower motor
harness connector.
Do approx. 12 volts exist
between blower motor har-
ness terminal No.
V1and
body ground?
No
.
Yes
Note
CHECK BODY GROUND CIRCUIT FOR
FAN CONTROL AMP.
Does continuity exist between fan control
amp. harness terminal No.
V1and body
ground?
YesCheck
power sup-
ply circuit
and 15A
fuses (No.21and22,
located in
the fuse
block).
Note
Reconnect fan control amp. harness con-
nector.
Check circuit continuity
between blower motor har-
ness terminal No.
V2and
fan control amp. harness
terminal No.
V3.
OK
CHECK FOR AUTO AMP. OUTPUT.
Set up Self-diagnosis STEP 4.
Measure voltage across fan control amp.
harness terminal No.
V2and body
ground.
OKCHECK BLOWER
MOTOR.
(Refer to HA-2067.)
NG
Replace blower motor.
cNGVA(Go to next page.)
Replace fan control amp.
Note:If the result is NG or No after checking circuit continuity, repair harness or
connector.
Code No.Terminal No.
VoltageÅ@
þ
V2Body groundApprox.
2.5-3VApprox.
9 - 10V
RHA087GB
RHA489H
RHA490H
RHA645GA
RHA523H
..
.
..
.
.
TROUBLE DIAGNOSESAUTO
Blower Motor (Cont'd)
HA-2065
VA
Disconnect auto amp. and fan control
amp. harness connector.
Note
Does continuity exist between auto amp.
harness terminal No.
V17and fan control
amp. harness terminal No.
V2?
Continuity should exist.
If OK, check harness for short.
Yes
CHECK FAN FEED BACK CIRCUIT.
Do approx. 12 volts exist between auto
amp. harness terminal No.
V20and body
ground?
Yes
cNo
Check power supply circuit
and 15A fuses (No.
21
and22, located in the fuse
block).
Refer to EL section (ªWir-
ing Diagramº, ªPOWER
SUPPLY ROUTINGº).
Note
Do approx. 12 volts exist between auto
amp. harness terminal No.
V18and body
ground?
Yes
cNo
Check circuit continuity
between blower motor har-
ness terminal No.
V2and
auto amp. harness terminal
No.
V18.
Continuity should exist.
If OK, check harness for
short.
Replace auto amp.
Note:
If the result is NG or No after checking circuit continuity, repair harness
or connector.
RHA491H
RHA648GA
RHA649GA
RHA650GA
RHA492H
.
.
.
.
.
TROUBLE DIAGNOSESAUTO
Blower Motor (Cont'd)
HA-2066
