TM 9-2350-287-20-1
2-19. TROUBLESHOOTING CHART (continued).
x. NBC SYSTEM (continued).
(2) ONE OR MORE M3 UNITS (ELECTRIC AIR
HEATERS) FAIL TO OPERATE. No flow from
M2A2 air purifier unit (continued).
CONTINUED FROM B
B. 5. Turn MASTER switch OFF (refer to TM 9-
2350-287-10).
I
Is voltage present?
I
1
Replace M3 electric air heater(s) (para 22-
3). Verify problem is solved.
C.
NOTE
Trace the electrical lead from the defective
M3 unit back to the harness connector pin
on the NBC control box (J2 connector).
Leads are numbered (415D to 415G) for
easy identification.
1. Reconnect wire harness 12330296 to input
connection of M3 unit(s).
2. Disconnect harness from NBC control box
J2 connector.
3. Place red lead of multimeter in sockets
A,C,E or F (depending on which M3 unit is
defective) of control box power box outlet
and ground black probe.
4. Turn MASTER switch and NBC POWER
switch ON (refer to TM 9-2350-287-10).
5. Check for 24 ± 3 vdc.
6. Turn MASTER switch and NBC power
switch OFF (refer to TM 9-2350-287-10).
Is voltage present?
Continued on next page
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