CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
EXTERNAL VEHICLE 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.
F Reconnect switch panel to gage panel and
miscellaneous switches wiring harness to main
switch panel. Disconnect wire 25 from main switch
panel side of horn switch. Place red lead of
multimeter in wire 25 and black lead to ground.
Turn MASTER switch on and check for voltage.
Turn MASTER switch OFF. If voltage is present, go
to step G. If voltage is not present, repair/replace
wire 25 of switch panel to gage panel and
miscellaneous switches wiring harness (see
paragraph 6-55 for dual voltage; 6-56 for single
voltage).
G Reconnect wire 25 to main switch panel side of horn
switch. Disconnect wire 25 from horn side of horn
switch. Place red lead of multimeter on terminal of
horn switch and black lead to ground. Turn
MASTER switch on, push horn switch, and check
for voltage. Turn MASTER switch OFF. If voltage
is present, go to step H. If voltage is not present,
replace horn switch (see paragraph 6-20).
H Reconnect wire 25 to horn side of horn switch.
Disconnect wire 25 from external vehicle horn.
Place red lead of multimeter in wire 25 and black
lead to ground. Turn MASTER switch on, push horn
switch, and check for voltage. Turn MASTER
switch OFF. If voltage is present, go to step I. If
voltage is not present, repair/replace wire 25 of
horn switch to horn lead assembly (see paragraph
6-20).
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