TM 5-3805-258-24-1
9 5 0 B O P E R A T O R ' S S T A T I O N
E L E C T R I C A L T R O U B L E S H O O T I N G
Troubleshooting the Bucket Positioner Circuit on the Machine
IF THE BUCKET POSITIONER DOES NOT KICKOUT, do the tests
that follow in order:
A. Check the fuse (found in the right hand side of the operator’s cab).
B. Check the distance between the magnet and the switch box. The dis-
tance must be 6.4 to 9.0 mm (.25 to .35 in. ) and the magnet must go
directly between the mounting bolts.
C. Move the magnet away from the switch box. With the main power
switch turned ON, move another magnet close to the ON position
(position C) of the switch to see if this causes the solenoid to activate.
Move the magnet close to the OFF position (position B) of the switch to
see if this causes the solenoid to deactivate. If the magnet causes the
solenoid to activate and deactivate, install a new magnet on the machine.
D. If the magnet did not make the solenoid activate, disconnect the switch
E.
F.
harness from the machine harness. Make an electrical test of the pins
and sockets in the plug of the machine harness. With the power switch
turned ON, Pin 2 and Socket 1 must each have power (use the 5P7277
Voltage Tester connected to machine ground); Pin 3 must not have
power. Turn the main power switch OFF and check for continuity to
machine ground on Pin 3 (use the 8S4627 Circuit Tester). If these pins
and sockets do not test correctly, look at the schematic and find the
causes.
If the machine harness testis correct but the kickout still does not work,
connect a (jumper) wire from the negative terminal (the P/B wire) of
the solenoid to machine ground. With the main power switch turned
ON, the solenoid must activate each time the wire is put to machine
ground. If the solenoid does not activate, check for +24 volts with the
5P7277 Voltage Tester at the positive (R/0 wire) terminal of the
solenoid. If voltage is present, replace the solenoid. If voltage is not
present, look at the schematic and find the causes.
If all of the other tests are correct, make a replacement of the 9G116
Switch Assembly.
IF THE BUCKET POSITIONER KICKS OUT THE FIRST TIME,
LATCHES UP, AND WILL NOT UNLATCH (the detent has kicked out
and will not go back in for the next cycle), do the tests that follow:
A. Check the distance between the magnet and the switch box; the distance
must be 6.4 to 10.0 mm (.25 to .39 in.). Make sure that the magnet goes
directly over the OFF position (position B).
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