MAINTENANCE OF M939 SERIES VEHICLES - OD1661 - LESSON 1/TASK 2
An error message would have indicated a
circuit, frozen starter, or a tight engine.
Since the word GO is still displayed, SGT Elliott is
to repeat the test procedure. After attempting to crank the
the word GO is still displayed.
This indicates that the
is not being energized.
At this point SGT Elliott is
to check the starter voltage.
Step 5. To check the starter voltage SGT Elliott dials 67 into the
TEST SELECT switches and presses the TEST button. She again attempts
to crank the engine and observes the displayed voltage.
voltage displayed is above 17 volts, SGT Elliott is directed to check
the starter negative cable drop.
First, SGT Elliott dials 89 into the TEST SELECT switches
and presses the TEST button.
Again she cranks the engine and
observes the display.
Since the cable drop is less than the limit
specified on the vehicle test card (VTC), SGT Elliott is directed to
replace the starter following the procedures contained in paragraph
4-3 of TM 9-2320-272-20-1.
After the starter has been replaced, SGT Elliott repeats the test
procedures to ensure that the malfunction has been corrected and that
no additional malfunctions exist.
Ether Start System Troubleshooting. In the following paragraphs
we will follow SSG Williams as he troubleshoots the ether starting
system for the malfunction ENGINE CRANKS BUT WILL NOT START IN COLD
WEATHER (FUEL SYSTEM OPERATING PROPERLY) to the conclusion that the
atomizer is defective.
Again the first thing that SSG Williams performs is to read DA Form
2404 and talk to the operator.
Once this has been done, he reads
through the troubleshooting procedure to determine the necessary
tools, special test equipment, and special tools.
particular troubleshooting procedure SSG Williams will need only a
mechanic's general toolbox.