CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
POWERPLANT WARNING HORN-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.
A Disconnect gage panel to bulkhead wiring harness from
warning horn relay. Place red lead of multimeter in
socket A of wire 26 and black lead to ground. Turn
MASTER switch on, start engine, set to idle, and check
for voltage. Turn engine and MASTER switch OFF. If
voltage is present, go to step G. If voltage is not present,
go to step B.
B Reconnect gage panel to bulkhead wiring harness to
warning horn relay. Open air inlet doors (TM 9- 2350-
256-10). Disconnect bulkhead to APU, master relay, and
rigger's lights wiring harness from bulkhead. Place red
lead of multimeter in socket H of wire 26 and black lead
to ground. Turn MASTER switch on, start engine, set to
idle, and check for voltage. Turn engine and MASTER
switch OFF. If voltage is present, go to step C. If
voltage is not present, go to step D.
C Reconnect APU control box to foot dimmer switch and
bulkhead wiring harness to bulkhead. Disconnect wire 26
of gage panel to bulkhead wiring harness from APU
control box to foot dimmer switch and bulkhead wiring
harness. Place red lead of multimeter in female
connector of wire 26 and black lead to ground. Turn
MASTER switch on, start engine, set to idle, and check
for voltage. Turn engine and MASTER switch OFF. If
voltage is present, repair/replace wire 26 of gage panel to
bulkhead wiring harness (see paragraph 6-45 for dual
voltage; 6-46 for single voltage). If voltage is not
present, repair/replace wire 26 of APU control box to foot
dimmer switch and bulkhead wiring harness (see
paragraph 6-79 for dual voltage; 6-80 for single voltage).
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