TM 1-1520-238-T-7
11–273
11–51.
BUCS ON INDICATORS – ARE NOT LIGHTED WITH BUCS TST SWITCH SET TO
11–51
PLT OR CPG
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-T-6
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 power quadrant ,set RTR BK switch to
BRAKE. With BUCS TST switch held to PLT,
check for 28 VDC at P688–121.
Is voltage present?
YES
Go to step 4.
NO
Go to step 2.
2. Check for open between P688–121 and
P170–A6.
Does open exist?
YES
Repair open wire between:
P170–A6 and P413–A13,
P413–A14 and J459–B5,
P459–B5 and P688–121.
(A326):
J10–A13 and TB1–19–E,
J10–A14 and TB1–19–F.
Go to paragraph 11–23.
NO
Go to step 3.
3. Check for open between P170–A7 and P173–b.
Does open exist?
YES
Repair open wire between:
P170–A7 and P173 SP1,
P173 SP1 and P173–b.
Go to paragraph 11–23.
NO
Replace pilot ASE panel
(TM 1-1520-238-23).
4. With BUCS TST switch on pilot ASE panel held
to CPG, check for 28 VDC at P686–121.
Is voltage present?
YES
Go to step 6.
NO
Go to step 5.
5. Check for open between P686–121 and
P170–A3.
Does open exist?
YES
Repair open wire between:
P170–A3 and P413–A9,
P413–A10 and J447–A17,
P447–A17 and P686–121.
(A326):
J10–A9 and TB1–19–J,
J10–A10 and TB1–19–M.
Go to paragraph 11–23.
NO
Replace pilot ASE panel
(TM 1-1520-238-23).
6. With BUCS TST switch held to PLT or CPG on
pilot ASE panel, check for 0.5 VDC at P18–40.
Is voltage present?
YES
Refer to TM 1-1520-238-T-6 to
troubleshoot pilot
caution/warning system.
NO
Go to step 7.
