TM 9-2540-207-14&P
C3 - VENT FAN FAULT
C3
Vent Impeller speed is below normal limits
CHECK/POSSIBLE CAUSE
REF.
REPAIR
1
With heater off, check for free rotation
of the Vent Impeller by spinning by
hand
5.2.6
5.2.4
If Vent Impeller does not rotate freely, and
ambient temperature is greater than 32°F
(0°C), replace Vent Fan Motor and Impeller
Restart Heater
If the ambient temperature is below 32°F
(0°C), check for and remove frost or other
obstructions
around
the
Vent
Impeller
Restart Heater
2
Check Wire Connector from the Vent
Fan Motor to the Electronic Vent Fan
Driver Board
5.2.5
Reconnect to the Electronic Vent Fan Driver
Board Restart Heater
3
Check Wire Connector from the
Electronic Vent Fan Driver Board to
Power Wiring Harness
5.2.5
5.5.6
Reconnect to Power Wiring Harness
Restart Heater
4
Check All wiring connections to
electronic boards including the two
controller boards (2 connectors)
5.2.5
Reconnect all wiring to correct electronic
boards or components Restart Heater
5
Defective Electronic Vent Fan Driver
Board
5.2.5
Replace Electronic Vent Fan Driver Board
Restart Heater
6
Defective Vent Fan Motor
5.2.6
Replace Vent Fan Motor
Restart Heater
7
Defective Power Wiring Harness
5.5.6
Replace Power Wiring Harness Restart
Heater
6-7
