M2/M3 BFV: TROUBLESHOOTING - OD1610 - LESSON 1/TASK 1
course of troubleshooting, for this and any other malfunction that may be
encountered while troubleshooting the M2/M3, numerous troubleshooting
pathways may be followed depending upon test results received.
One afternoon an infantry fighting vehicle (IFV) arrives in the shop with
inoperative firing port vent fans. After reading DA Form 2404 and talking
with the operator/crew, SSG Taylor (our fictional individual) determines
that a malfunction actually exists.
After making this determination, SSG
Taylor turns to the Troubleshooting Systems Trees, beginning on page 3-15 of
the TM. He locates the troubleshooting procedures for the firing port vent
fans on page 3-26.
Once the proper troubleshooting procedures have been found, SSG Taylor reads
through the Initial Setup section to see what tools, materials/parts,
personnel, and references he will need, and also how the equipment should be
From this section, he sees that he will need a general
mechanic's automotive toolkit, inspection mirror, multimeter, electrical
connector pliers, and a jumper wire.
He will also need a helper and TM
9-2350-252-10-1. The vehicle should be parked with the engine stopped and
the FIRE SUPPRESSION switch in the MANUAL position.
After the necessary assistance, tools, and equipment have been gathered
together, SSG Taylor begins with the first step in the troubleshooting
procedure. This step directs him to place the MASTER POWER switch in the ON
position. Once the MASTER POWER switch is-on, step 2 directs him to lower
the ramp, following the procedures contained in TM 9-2350-252-10-1.
this is done, he moves on to steps 3 and 4 which direct him to pull the
firing port vent levers up to the open position, and to place the GUN PORT
VENT FAN switches in the ON position.
Now he moves on to step 5 which
questions if both of the gun port vent fans are operating. Since SSG Taylor
observes that both fans are operating, the answer to this question is "yes."
SSG Taylor would then follow the yes arrow to reference letter A where he is
asked the question, "Is air being drawn through each firing port vent