MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
Since battery voltage was not indicated, SSG Heatherly sets the
the negative battery terminal and connects the positive meter lead to
circuit 568 wire and the negative meter lead to the circuit 5
At this point, the meter should indicate
Since continuity is not indicated, this indicates that
there is an OPEN circuit.
He repairs circuit 568 as per the
instructions in paragraph 4-49 of TM 9-2320-272-20-1.
the malfunction HEADLAMPS (BOTH SIDES) INOPERATIVE and reaches the
conclusion that the headlamp beam selector switch is defective and
needs to be replaced.
The first thing that SGT Yowell does is read DA Form 2404 and
talk with the operator.
Once he has a better understanding of
the malfunction, he reads through the troubleshooting procedures to
determine the tools and special equipment necessary for this
For this particular troubleshooting procedure, SGT Yowell