CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
APU STARTING SYSTEM-Continued
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.
H
Reconnect wire 65A to APU START switch side of
circuit breaker. Disconnect wire 65 from panel
connector side of 15 A circuit breaker. Place red lead
of multimeter in wire 65 and black lead to ground.
Turn MASTER and PREHEAT switches ON, and check
for voltage. Turn MASTER and PREHEAT switches
OFF. If voltage is not present, go to step I. If voltage
is present, replace 15 A circuit breaker (see paragraph
13-7).
I
Disconnect APU control box to foot dimmer switch and
bulkhead wiring harness from APU control box. Place
red lead of multimeter in socket B of wire 65 and black
lead to ground. Turn MASTER and PREHEAT
switches on, and check for voltage. Turn MASTER
and PREHEAT switches OFF. If voltage is present,
repair/replace wire 65 of APU control box. If voltage is
not present, go to step J.
J
Reconnect APU control box to foot dimmer switch and
bulkhead
wiring
harness
to
APU
control
box.
Disconnect wire 487 from 15 A circuit breaker. Place
red lead of multimeter on terminal of 15 A circuit
breaker and black lead to ground. Turn MASTER and
PREHEAT switches ON, and check for voltage. Turn
MASTER and PREHEAT switches OFF. If voltage is
present, repair/replace wire 487 of APU control box
wiring harness (see paragraph 13-7). If voltage is not
present, go to step K.
2-166