CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
TM 9-2350-256-20
2-19 ELECTRICAL TROUBLESHOOTING-Continued
M239 SMOKE GRENADE LAUNCHER 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.
D
Place a jumper wire from pin A to socket A. Place red
lead of multimeter on pin B of M239 launcher power
switch box and black lead to ground. Turn MASTER
and ARM SMOKE switches ON and check for voltage.
Place red lead of multimeter on pin D of ARM SMOKE
box assembly and black lead to ground and check for
voltage. Turn MASTER and ARM SMOKE switches
OFF. If voltage is present on both pins, go to step F. If
voltage is not present on either pin, go to step E.
E
Reconnect smoke grenade launcher system wiring
harness to M239 launcher power switch box. Remove
M239 launcher power switch box from mounting bracket
(see paragraph 15-1). Disconnect connector from
terminal 2 of ARM SMOKE switch. Place red lead of
multimeter on wiring harness and black lead to ground.
Turn MASTER switch on and check for voltage. Turn
MASTER switch OFF. If voltage is not present,
repair/replace wire in power switch box assembly for
M239 smoke grenade launcher assembly (see
paragraph 6-92). If voltage is present, replace ARM
SMOKE switch (see paragraph 15-1).
F
Reconnect smoke grenade launcher system wiring
harness to M239 launcher power switch box.
Disconnect smoke grenade launcher system wiring
harness from FIRE SMOKE box assembly. Place red
lead of multimeter in socket B and black lead to ground.
Turn MASTER and ARM SMOKE switches ON and
check for voltage. Place red lead of multimeter in
socket D and black lead to ground and check for
voltage. Turn MASTER and ARM SMOKE switches
OFF. If voltage is present in both sockets, go to step G.
If voltage is not present in either socket, repair/replace
smoke grenade launcher system wiring harness (see
paragraph 6-91).
2-340
