TM 1-1520-238-T-4
4–103
4–22.
ENG START ENG NO 1 INDICATOR – REMAINS LIGHTED ABOVE 52% NG
4–22
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
Equipment Conditions:
Ref
Condition
TM 1-1520-238-23
Access provisions –
LN1 door open
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 P64. Set and hold ENG START NO 1
switch to IGN OVRD. Check for 1
0.1 VAC
between P64–E and P64–F.
Is voltage present?
YES
Go to step 3.
NO
Go to step 2.
2. Check for open between:
P64–E and J21–29,
P64–F and J21–28.
Does open exist?
YES
Repair open wire.
Go to paragraph 4–12.
NO
Go to step 5.
3. Place ENG START NO 1 switch to OFF. Check
for short between P21–25 and P21–26.
Does short exist?
YES
Go to step 4.
NO
Go to step 6.
4. Detach P39. Check for short between:
P39–3 and ground,
P39–4 and ground.
Does short exist?
YES
(AFC) Repair shorted wire.
Go to paragraph 4–12.
(AFD) Replace wire harness
(TM 1-1520-238-23).
NO
Replace engine starter air
pressure regulator valve
(TM 1-1520-238-23).
5. Check for open between:
P21–28 and P35–3,
P21–29 and P35–5.
Does open exist?
YES
(ABY) Repair open wire.
Go to paragraph 4–12.
(ABZ) Replace wire harness
(TM 1-1520-238-23).
NO
Replace air turbine starter
(TM 1-1520-238-23).
6. Have assistant place ENG START NO 1 switch
to IGN OVRD. Check for 28 VDC at P39–2.
Is voltage present?
YES
Replace relay (A330)K1–5/6
(TM 1-1520-238-23).
NO
Go to step 7.
7. Have assistant set and hold ENG START
NO 1 switch in IGN OVRD. Check for
28 VDC at P21–24.
Is voltage present?
YES
(ABY) Repair open wire.
Go to paragraph 4–12.
(ABZ) Replace wire harness
(TM 1-1520-238-23).
NO
Replace flow turbine start switch
(TM 1-1520-238-23).
END OF TASK
