TM
9-2320-363-20-1
Table 3-1.
Troubleshooting
(Cont)
Malfunction
Test or Inspection
Corrective Action
ELECTRICAL SYSTEM (CONT)
Auxiliary
Heater Circuits (Cont)
1.
AUXILIARY HEATER DOES NOT OPERATE, AUXILIARY LIGHTS OPERATING.
Step
1.
Check
auxiliary
heater
25A fuse.
.
If defective,
replace
25A fuse (page
4-204).
Step 2.
Remove
auxiliary
heater
25A fuse. Check for +24
VDC at fuse connector
to
24
V constant
power
bus.
l
if +24
VDC
is present, go to step 3. If no voltage
is present,
repair
lead (page 3-2).
Step 3.
Disconnect
lead 58 from auxiliary heater.
Check
for +24
VDC at lead 58.
.
if +24
VDC is present, go to step 4. If no voltage
is present,
repair
lead 58 (page 3-2).
Step 4.
Disconnect
leads 58 and 58E from auxiliary heater
on/off switch.
Check
for
continuity
between
contacts
of auxiliary heater on/off switch.
.
if continuity
is indicated, go to step 5. If no continuity is
indicated,
replace
auxiliary heater on/off switch (page
4-190).
Step
5.
Disconnect
24 V auxiliary
heater power relay from connector.
Check
for
+24
VDC
at connector
30 and 85 with auxiliary
heater
on/off switch closed.
.
if +24
VDC
is present,
go to step 6. If no voltage
is present,
repair
lead 422
or lead 58E
(page
3-2).
Step 6.
Disconnect
24 V auxiliary
heater
high relay from connector.
Check
for
+24
VDC
at connectors
30 and 85 with
auxiliary
heater
on/off switch closed
and
auxiliary
heater
high/low switch in high mode.
.
If +24
VDC
is present,
go to step 7. If no voltage
is present
at connector
30,
repair lead 422
(page
3-2).
If no voltage
is
present
at connector 85, go to next corrective
action.
.
Disconnect
lead 58E from auxiliary
heater
high/low switch.
Check for +24 VDC at auxiliary
heater
high/low
switch. If
+24
VDC
is present,
go to next corrective
action.
If no voltage
is present,
repair lead 58E (page
3-2).
.
Disconnect
lead 58A from auxiliary
heater
high/low switch.
Check
for +24
VDC
at auxiliary heater
high/low
switch. If
+12
VDC
is present,
go to step 7. If no voltage
is present,
repair
lead 58A
(page 3-2).
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