SECTION V: TROUBLESHOOTING
TM 9-2350-256-20
WARNING
Remove all jewelry such as rings, dog tags, bracelets, etc.
If jewelry contacts a metal surface a direct short may result
in instant heating of tools, damage to equipment, and injury
or death to personnel.
I
Reconnect APU control box to foot dimmer switch and
bulkhead wiring harness to APU control box. Install
APU control box (9), four screws (8), four lockwashers
(7), and four nuts (6) to mounting bracket. Open air
inlet doors. Disconnect bulkhead to APU, master relay,
and rigger's lights wiring harness from bulkhead
disconnect. Place red lead of multimeter on pin F of
wire 421 and black lead to ground. Turn MASTER and
APU fuel shut-off switches ON and check for voltage.
Turn MASTER and APU fuel shut-off switches OFF. If
voltage is present, go to step J. If voltage is not
present, repair/replace wire 421 of APU control box to
foot dimmer switch and bulkhead wiring harness (see
paragraph 6-79 for dual voltage; 6-80 for single
voltage).
J
Reconnect bulkhead to APU, master relay, and rigger's
lights wiring harness to bulkhead disconnect. Open
center-front air inlet doors (TM 9-2350-256-10).
Disconnect bulkhead to APU, master relay, and rigger's
lights wiring harness from APU engine disconnect.
Place red lead of multimeter on pin B of wire 421 and
black lead to ground. Turn MASTER and APU fuel
shut-off switches ON and check for voltage. Turn
MASTER and APU fuel shut-off switches OFF. If
voltage is present, notify Direct Support Maintenance.
If voltage is not present, repair/replace wire 421 of
bulkhead to APU, master relay, and rigger's lights
wiring harness (see paragraph 6-75 for dual voltage; 6-
76 for single voltage).
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