TM
9-2320-363-20-1
Table 3-1.
Troubleshooting
(Cont)
Malfunction
Test or Inspection
Corrective Action
ELECTRICAL SYSTEM (CONT)
Standard
Heater Circuits (Cont)
Step 12.
Disconnect lead 98T from heater
fan
motor.
Check
for +12
VDC
at lead
98T with heater
fan control in high mode.
.
If +12
VDC
is present, go to step 13.
If no voltage
is present,
disconnect
heater fan high relay from connector.
Check
for
continuity
in lead 98T between
connector
30 and heater
fan
motor. If continuity is indicated,
replace
heater
fan high relay
(pages
4-197,
4-198).
If no continuity
is indicated,
repair
lead
98T
(page 3-2).
Step
13.
Disconnect
ground lead from heater fan motor. Check
for continuity
2.
NONE
OF THE
Step
1.
Step
2.
Step
3.
Step
4.
between
ground lead and ground.
.
If continuity is indicated,
replace
heater
fan motor (page
4-192).
If no continuity is indicated,
repair ground
lead (page
3-2).
LOWER
VARIABLE
SPEEDS
OPERATE.
Disconnect
leads
98Y,
98E,
and 98F
from heater
fan control.
Check
for
+12
VDC
at connector
(E) with heater
fan control
in low mode,
at
connector
(C) with heater
fan control in medium
mode,
and at connector
(F)
with heater
fan control in medium-high
mode.
.
If +12
VDC
is present, go to step 2. If no voltage
is present,
replace
heater
fan
control
(page
4-1
90).
Disconnect
lead
98L
from
heater
fan
control.
Check
for
+12
VDC with heater
fan control in low, medium,
and medium-high
mode.
.
If +12
VDC
is present,
replace
heater
fan
control
(page
4-190).
If
no
voltage
is
present,
go
to
step
3.
Disconnect
lead
98R
from
heater
fan
resistor
block. Check
for +12
VDC
with
heater fan control in low mode.
.
If +12 VDC
is present, go to step 4.
If no voltage
is present,
replace
heater fan resistor block (notify direct support
maintenance).
Disconnect
heater
fan high relay from connector.
Check
for +12 VDC
at
connector
87A.
.
If +12
VDC
is present, go to step 5. If no voltage
is present,
repair lead 98R
(page 3-2).
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