TM 1-1520-238-T-6
9–274
9–83.
LT SRCH/LDG CONTR CIRCUIT BREAKER (CB80) – DOES NOT STAY CLOSED
9–83
Tools:
Nomenclature
Part Number
Tool Kit, Electrical
SC518099CLA06
Repairer’s
Multimeter, Digital
AN/PSM-45
Personnel Required:
68X
Armament/Electrical Systems Repairer
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 circuit breaker panel, open LT
SRCH/LDG CONTR circuit breaker (CB80).
Check for short between (A76)J1-V and ground.
Does short exist?
YES
Go to paragraph 9–263 to
troubleshoot circuit protection
system (dc emergency bus –
pilot station).
NO
Go to step 2.
2. Detach wire from (A326)TB1-24-F. Check for
short between P463-V and ground.
Does short exist?
YES
Repair shorted wire.
Go to paragraph 9–80.
NO
Go to step 3.
3. Detach wire from (A326)TB1-24-A. Check for
short between wire end at (A326)TB1-24-A and
ground.
Does short exist?
YES
Go to step 4.
NO
Go to step 6.
4. With relay (A326)K1-1/2 removed, check for
short between (A326):
XK1-1/2-A2 and case,
XK1-1/2-X1 and case.
Does short exist?
YES
Replace landing/searchlight
relay (A326)K1-1/2.
NO
Go to step 5.
5. Detach wire from DS11-3. Check for short
between wire end at (A326)TB1-24-A and
ground.
Does short exist?
YES
Repair shorted wire between:
DS11-3 and P466-A9,
(A326):
J14-A9 and TB1-23-A,
TB1-23-K and TB1-24-A,
TB1-23-D and XK1-1/2-A2,
TB1-23-G and XK1-1/2-X1.
Go to paragraph 9–80.
NO
Replace landing/search light
(TM 1-1520-238-23).
6. Identify and detach wires from (A326):
TB1-24-J and TB1-24-K.
Check for short between wire end at (A326):
TB1-24-J and ground,
TB1-24-K and ground.
Does short exist?
YES
Go to step 9.
NO
Go to step 7.
7. Check for short between P107-s and ground.
Does short exist?
YES
Replace pilot SRCH LT switch
(S4) (TM 1-1520-238-23).
NO
Go to step 8.
