TM 9-2320-302-20
0010 00-18
Table 1. Electrical System Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Standard Heater Circuits - Continued
Heater Fan Does Not Operate at Any Speed -
Continued.
4. Remove start/auxiliary 15A
fuse. Check for +12 VDC at
lead 71A fuse connector.
If +12 VDC is present, go to step
5. If voltage is not present, repair
lead 71A (WP 0119 00).
5. Disconnect heater fan power
relay from connector. Check
for +12 VDC at connector 30.
If +12 VDC is present, go to step
6. If voltage is not present, repair
lead 98 (WP 0119 00).
6. Disconnect heater fan high
relay from connector. Check
for +12 VDC at connector 87.
If +12 VDC is present, go to step
7. If voltage is not present, repair
lead 98 (WP 0119 00).
7. Check for continuity between
connector 86 and ground for
both relays.
If continuity is indicated, go to
step
8.
If
continuity
is
not
indicated, repair ground lead (WP
0119 00).
8. Disconnect heater fan power
relay from connector. Check
for +12 VDC at connector 85.
If +12 VDC is present, go to step
9. If voltage is not present, repair
lead 71A (WP 0119 00).
9. Disconnect
lead
98
from
heater fan control. Check for
+12 VDC at lead 98.
If +12 VDC is present, go to step
10. If voltage is not present,
disconnect heater fan power relay.
Check for continuity in lead 98. If
continuity is indicated, replace
heater fan power relay (WP 0071
00). If continuity is not indicated,
repair lead 98 (WP 0119 00).
10. Disconnect lead 98L from
heater fan control. Check for
+12 VDC at heater fan control
connector (D) with heater fan
control in high mode.
If +12 VDC is present, go to step
11. If voltage is not present,
replace heater fan control (WP
0067 00).
11. Disconnect heater fan high
relay from connector. Check
for +12 VDC at connector 85
with heater fan control in high
mode.
If +12 VDC is present, go to step
12. If voltage is not present, repair
lead 98L (WP 0119 00).
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 voltage is not 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 (WP
0071 00). If continuity is not indi-
cated, repair lead 98T (WP 0119 00).
