M2/M3 BFV: TROUBLESHOOTING - OD1610 - LESSON 1/TASK 2
flashing display reads 1000 to 1200 rpm. Observe and note the other reading
flashing on the display.
This is the battery voltage with the engine
running. If the display had shown 0 volts, we would turn to the STE-M1/FVS
(VTM only) test number 67 diagnostic troubleshooting procedures on page
3-981 of TM 9-23520-252-20-1-1.
If the display shows any other value except for 0, turn off the service
drive lights and stop the engine.
Then return to the troubleshooting
procedures that were being followed.
(4) VTM Test Number 68. This test is used to test the starter relay
coil switch voltage and the starter positive terminal voltage.
paragraphs that follow, the procedures for performing each of these tests
will be discussed.
(a) Starter Relay Coil Switch Voltage. To perform this test, the
vehicle should be parked with the engine stopped and the tracks chocked.
Once the vehicle is configured for testing, connect the VTM to DCA 13. In
the previous test, the VTM had to be connected to DCA 3; this time the VTM
must be connected to DCA 13.
Once the VTM is connected, set the TEST SELECT switches to 68, then press
and release the TEST button.
Now place the MASTER POWER switch and the
ENGINE ACCESSORY switch in the ON positions.
Now move the gear selector
lever to the START position. The engine should crank.
Holding the gear selector lever in the START position
for more than 30 seconds can damage the starter. If
the engine does not start on the first try, wait 1
minute then try again.
At this point, check the display. Test number 68 passes when the display
reads 17 or more volts.
Place the gear selector lever in the NEUTRAL
position and place the ENGINE ACCESSORY and the MASTER POWER switches to the
OFF positions. Then return to the troubleshooting procedure that was