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 802 of 1313
HEADLAMP (ONE SIDE) INOPERATIVE - Continued
STEP
2.
IS THERE BATTERY VOLTAGE AT HEADLAMP CONNECTOR?
a.
Place battery switch to OFF position.
T0752DAA
Figure 2.
Headlamp Connectors.
b.
Disconnect circuit 18 and 17 wire at inoperative headlamp.
c.
Make sure wire connector contacts are clean.
d.
Place battery switch to ON position.
e.
Place lighting switch to SERVICE DRIVE position and press beam select switch to LOW BEAM.
f.
Set up multimeter to measure VDC.
g.
Connect multimeter red lead to circuit 18 wire. Refer to point to point schematics.
h.
Connect multimeter black lead to good ground.
i.
Meter reading should be greater than 18 VDC. Note reading.
j.
Press beam select switch to HIGH BEAM.
k.
Connect multimeter red lead to circuit 17 wire.
l.
Connect multimeter black lead to good ground.
m.
Meter reading should be greater than 18 VDC. Note reading.
CONDITION/INDICATION
IS THERE BATTERY VOLTAGE AT HEADLAMP CONNECTOR?
DECISION
NO - Repair or replace loose or corroded connections and wiring from headlamp to beam select
switch (Volume 3, WP
0352). Go to Step (3) to verify problem is solved.
YES - Replace defective headlamp (Volume 2, WP
0325). Go to Step (3) to verify problem is solved.
TM 9-2320-272-23-1
0092
0092-3
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