TM-9-2320-272-23-1
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-1 - Page 847 of 1313
NO LIGHTS OPERATE WITH DIRECTIONAL SIGNAL CONTROL LEVER IN ANY POSITION - Continued
STEP
4.
IS MAIN LIGHT SWITCH OPERATING PROPERLY?
a.
Place battery switch to OFF position.
C
B
A
K
E
T1027DAA
F
N
M
L
H
Figure 4.
Main Lighting Switch Connector.
b.
Connect jumper cable from socket pin F to socket pin J. Refer to point to point schematics.
c.
Place battery switch to ON position.
d.
Connect multimeter red lead to control unit harness connector socket pin G.
e.
Connect multimeter black lead to good ground.
NOTE
If meter reading is greater than 18 VDC, main light switch is faulty.
f.
Meter reading should be greater than 18 VDC.
CONDITION/INDICATION
IS MAIN LIGHT SWITCH OPERATING PROPERLY?
DECISION
NO - Replace defective main light switch (Volume 2, WP
0315). Go to Step (9) to verify problem is solved.
YES - Repair or replace wiring from main light switch to control unit (Volume 3, WP
0352). Go to Step (9) to
verify problem is solved.
TM 9-2320-272-23-1
0098
0098-4
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