CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
B.O. SERVICE CONDITION (IR HEADLIGHTS)-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.
E
Reconnect headlight base assembly to headlight
assembly. Disconnect headlight and dimmer
switch wiring harness from dimmer switch. Place
a jumper wire from socket C to pin C of wire
514/515. Place red lead of multimeter on pin A of
wire 515 and black lead to ground. Turn MASTER
switch on, UNLOCK and move main lighting
switch to B.O. DRIVE position, B.O. SELECTOR
switch to IR, and check voltage. Turn MASTER,
main lighting, and B.O. SELECTOR switches off.
If voltage is present, go to step G. If voltage is
not present, go to step F.
F
Place a jumper wire from socket C to pin C of wire
514/515. Place red lead of multimeter on pin B of
wire 514 and black lead to ground. Turn MASTER
switch on, UNLOCK and move main lighting
switch to B.O. DRIVE position, B.O. SELECTOR
switch to IR, press dimmer switch, and check for
voltage. Turn MASTER, main lighting, B.O.
SELECTOR, and dimmer switches off. If voltage
is present, go to step H. If voltage is not present,
go to step I.
G Reconnect headlight and dimmer switch wiring
harness to dimmer switch. Disconnect wire 515 of
headlight base assembly at connector. Place red
lead of multimeter in wire 515 and black lead to
ground. Turn MASTER switch on, UNLOCK and
move main lighting switch to B.O. DRIVE
position, B.O. SELECTOR switch to IR, and
check for voltage. Turn MASTER, main lighting,
and B.O. SELECTOR switches off. If voltage is
present, repair/replace wire 515 of headlight base
wiring harness (see paragraph 6-64). If voltage is
not present, repair/replace wire 515 of headlight
and dimmer switch wiring harness (see paragraph
6-65).
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