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 805 of 1313
HEADLAMP (BOTH SIDE) INOPERATIVE - Continued
STEP
1.
IS HEADLAMP WIRING HARNESS IN GOOD CONDITION?
a.
Place battery switch to OFF position.
T0755DAA
Figure 1.
Beam Select Switch.
b.
Disconnect circuit 18 and 17 wire at beam selector switch.
c.
Place battery switch to ON position.
d.
Place lighting switch to SERVICE DRIVE position and press beam select switch to LOW BEAM.
e.
Set up multimeter to measure VDC.
f.
Connect multimeter red lead to circuit 18 terminal on switch. Refer to point to point schematics.
g.
Connect multimeter black lead to good ground.
NOTE
If meter reading is greater than 18 VDC for both measurements, headlamp wiring
harness is faulty.
h.
Meter reading should be greater than 18 VDC. Note reading.
i.
Press beam select switch to HIGH BEAM.
j.
Connect multimeter red lead to circuit 17 terminal on switch.
k.
Connect multimeter black lead to good ground.
l.
Meter reading should be greater than 18 VDC. Note reading.
CONDITION/INDICATION
IS HEADLAMP WIRING HARNESS IN GOOD CONDITION?
TM 9-2320-272-23-1
0093
0093-2
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