TM
9-2320-363-20-1
Table 3-1.
Troubleshooting
(Cont)
Malfunction
Test or Inspection
Corrective Action
Step 4.
Step 5.
Step 6.
Step 7.
Step 8.
Step 9.
ELECTRICAL SYSTEM (CONT)
Standard Heater Circuits (Cont)
Remove
start/auxiliary
15A fuse. Check for
connector.
.
If +12
VDC
is present,
go
to
repair
lead
71A
(page
3-2).
+12 VDC at lead 71A fuse
step 5. If no voltage
is
present,
Disconnect
heater
fan power relay from connector. Check for +12
VDC
at
connector
30.
.
If +12
VDC
is present,
go to step 6. If no voltage
is present,
repair lead 98 (page 3-2).
Disconnect
heater
fan high relay from connector. Check for +12
VDC
at
connector
87.
.
If +12
VDC
is present,
go
to
step
7.
If no voltage
is present,
repair lead 98 (page 3-2).
Check
for continuity
between
connector
86 and ground for both relays.
.
If continuity is indicated,
go to step 8. If no continuity
is
indicated,
repair ground lead (page 3-2).
Disconnect
heater
fan power relay from connector. Check for +12
VDC
at
connector
85.
.
If +12
VDC
is present,
go to step 9. If no voltage
is present,
repair lead 71 AA (page 3-2).
Disconnect
lead 98 from heater fan control. Check for +12 VDC
at lead 98.
Step 10.
Disconnect
fan control
l
Step 11.
Disconnect
If +12
VDC
is present, go to step 10. If no voltage
is present,
disconnect
heater fan power relay. Check for continuity
in
lead 98.
If continuity is indicated,
replace heater fan power
relay (pages
4-197,
4-198).
If no
continuity
is indicated,
repair
lead
98
(page
3-2).
lead 98L from heater fan control. Check for +12 VDC
at heater
connector
(D) with heater fan control in high mode.
If +12 VDC
is present,
go to step 11. If no voltage
is present,
replace
heater fan control (page 4-190).
heater
connector
85 with
l
If +12
repair
fan high relay from connector. Check for +12
VDC
at
heater fan control in high mode.
VDC
is present,
go to step 12. If no voltage
is present,
lead 98L (page 3-2).
3-71
