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 806 of 1313
HEADLAMP (BOTH SIDE) INOPERATIVE - Continued
DECISION
NO - Repair or replace loose or corroded connections and wiring from headlamps to beam select
switch (Volume 3, WP
0352). Go to Step (6) to verify problem is solved.
YES - Go to Step (2).
STEP
2.
IS THERE BATTERY VOLTAGE AT CIRCUIT 16 WIRE?
a.
Place battery switch to OFF position.
T0755DAA
Figure 2.
Beam Select Switch.
b.
Disconnect circuit 16 wire from beam selector switch.
c.
Inspect and make sure circuit wire 16 is in good condition.
d.
Place battery switch to ON position.
e.
Place lighting switch to SERVICE DRIVE position.
f.
Connect multimeter red lead to circuit 16 wire (not the switch terminal). Refer to point to point schematics.
g.
Connect multimeter black lead to good ground.
h.
Meter reading should be greater than 18 VDC.
CONDITION/INDICATION
IS THERE BATTERY VOLTAGE AT CIRCUIT 16 WIRE?
DECISION
NO - Go to Step (3).
YES - Replace beam selector switch (Volume 2, WP
0316). Go to Step (6) to verify problem is solved.
TM 9-2320-272-23-1
0093
0093-3
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