TM 5-3805-280-24-1
Sub-System Diagnostics
ECONOMY (E) MODE SWITCH (S11)
DRIVE AND WORK LIGHT SWITCH (10)
When the economy (E) mode switch is pressed, a
The drive and work light switch provides ground
ground is applied from engine mode and RPM control
switched outputs to the light circuits. When the switch
unit terminal 2 to monitor controller terminal 35,
is moved to position 1, controller terminal 19 (drive
causing the economy mode to be selected. With the
light) is grounded. When the switch is moved to
economy mode selected, the monitor controller
position 2, controller terminals 19 and 20 (work light)
illuminates the economy mode indicator light (H6), and
are grounded.
provides an output signal to the engine and pump
controller from terminal 15. Ground for the mode
WORK MODE SELECTION SWITCH (S7)
switch is applied to engine mode and RPM control unit
terminal 1.
The work mode selection switch selects the machine
operating modes (dig, grading, precision, or
HIGH POWER (HP) MODE SWITCH (S12)
attachment). Each time the switch is pressed the mode
selection is stepped to the next mode and the
When the high power (HP) mode switch is pressed, a
corresponding mode indicator (H1, H2, H3 or H4) is
9015
ground is applied from engine mode and RPM control
illuminated. The monitor controller provides different
15
unit terminal 4 to monitor controller terminal 34,
combinations of ground switched outputs to the engine
49
causing the high power mode to be selected. With the
and pump controller depending on the mode selected.
high power mode selected, the monitor controller
The outputs are applied to mode 1 and mode 2
illuminates the high power mode indicator light (H5),
monitor controller terminals 21 and 22.
and provides an output signal to the engine and pump
controller from terminal 23. Ground for the mode
PROPEL SPEED CHANGE SWITCH (S8)
switch is applied to engine mode and RPM control unit
terminal 3
The propel speed change switch selects slow or fast
operating speed. When the switch is moved to fast
ENGINE RPM DIAL (R10)
speed, the monitor controller speed selection output to
the engine controller at terminal 17 is grounded.
The engine RPM dial provides a variable voltage to
engine and pump controller terminal D21 from engine
AUTO IDLE (A/I) SWITCH (S13)
mode and RPM control unit terminal 6 based on the
setting of the RPM dial. Power for the RPM dial is
When the auto idle (A/I) switch is pressed, the A/I
applied across engine mode and RPM control unit
indicator illuminates and the monitor controller provides
terminals 5 and 7.
a ground output to the engine motor and pump
controller from terminal 13.
ENGINE MODE AND RPM CONTROL UNIT (A4)
CED,OUOE012,27 1902NOV983/3
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