TM 1-1520-238-T-6
9–759
9–397. ENG WARN CIRCUIT BREAKER (CB52) – DOES NOT STAY CLOSED
9–397
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. Detach P463. On pilot center circuit breaker
panel, check that ENG WARN circuit breaker
(CB52) is closed.
Does circuit breaker stay closed?
YES
Go to step 2.
NO
Go to paragraph 9–263 to
torubleshoot dc emergency bus
– pilot station.
2. Detach P49. Check for short between P463-N
and ground.
Does short exist?
YES
(AAT) Go to step 3.
(AAV) Go to step 4.
NO
Replace engine out warning unit
(TM 1-1520-238-23).
3. (AAT) Detach wire ends at (A326):
TB1-51-D and TB1-51-E. Check for short
between:
P463-N and ground,
P49-14 and ground,
(A326)J2-A10 and ground,
(A326)J7-A15 and ground.
Does short exist?
YES
Repair shorted wire between:
P463-N and P469-A10,
P49-14 and P435-A15.
(A326):
J2-A10 and TB1-51-E,
J7-A15 and TB1-51-D.
Go to paragraph 9–395.
NO
Replace relay (A326)TB1-15
(TM 1-1520-238-23).
4. (AAV) Detach P469. Detach wire ends at
(A326):
TB1-51-D, TB1-51-E and TB1-51-F. Check for
short between:
P463-N and ground,
P49-14 and ground,
(A326)J2-A10 and ground,
(A326)J7-A15 and ground,
(A326)J2-A18 and ground.
Does short exist?
YES
Repair shorted wire between:
P463-N and P469-A10,
P49-14 and P435-A15,
(A326)J2-A10 and
(A326)TB1-51-E,
(A326)J7-A15 and
(A326)TB1-51-D,
(A326)J2-A18 and
(A326)TB1-51-F.
Go to paragraph 9–395.
NO
Replace relay (A326)TB1-51
(TM 1-1520-238-23).
END OF TASK
