TM 1-1520-238-T-6
9–583
9–290. LT UTIL SEC CIRCUIT BREAKER (CB23) – DOES NOT STAY CLOSED OR
9–290
28 VDC IS NOT PRESENT AT (A76): J1-U AND J1-W
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
One person to assist
References:
TM 1-1520-238-23
WARNING
Turn off power before detaching or
attaching wires and connectors. High
current 28 VDC or 115 VAC is present.
Failure to do so could result in death or
serious injury.
1. On pilot ELEC PWR panel, set BATT/EXT PWR
switch to EXT PWR.
Does LT UTIL SEC circuit breaker (CB23)
stay closed?
YES
Go to step 4.
NO
Go to step 2.
2. On pilot center circuit breaker panel, open LT
UTIL SEC circuit breaker (CB23). Set
BATT/EXT PWR switch to OFF. Check for short
between (A76):
J1-U and ground,
J1-W and ground.
Does short exist?
YES
Go to step 3.
NO
Go to paragraph 9–103 to
troubleshoot pilot utility and
secondary lights.
3. Detach wire at CB23-2. Check for short between
(A76):
J1-U and ground,
J1-W and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–263.
NO
Replace LT UTIL SEC circuit
breaker (CB23)
(TM 1-1520-238-23).
4. Set BATT/EXT PWR switch to OFF. Check for
open between:
CB23-2 and (A76)J1-U,
CB23-2 and (A76)J1-W.
Does open exist?
YES
Repair open wire.
Go to paragraph 9–263.
NO
Replace LT UTIL SEC circuit
breaker (CB23)
(TM 1-1520-238-23).
END OF TASK
