TM 5-3805-280-24-1
Sub-System Diagnostics
HYDRAULIC OIL FILTER RESTRICTION INDICATOR
HYDRAULIC OIL LEVEL INDICATOR (H12)
(H21)
Hydraulic oil level switch (B5) is a normally open
The hydraulic oil filter restriction switch (B30) is a
switch, held closed when the oil level is adequate. The
normally open switch that closes to machine ground
machine ground is applied to controller terminal 9. The
when the differential pressure in the hydraulic oil filter
monitor controller only checks the status of terminal 9
exceeds 15 psi. The machine ground is applied
when the fluid level switch (S5) is pressed. If ground is
through switch B31 to controller pin 43, causing the
present when the switch is pressed, the indicator
indicator to illuminate.
illuminates.
MONITOR CONTROLLER AND DISPLAY ALARM
ENGINE COOLANT LEVEL INDICATOR (H20)
(H8)
Engine coolant level switch (B6) is a normally open
The monitor controller and display alarm sounds when
switch, held closed when the coolant level is adequate.
the engine oil pressure is low, or the engine coolant
The machine ground is applied to controller terminal 8.
overheats. When the buzzer stop switch (S6) is
The monitor controller only checks the status of
9015
pressed and released, the buzzer stops sounding and
terminal 8 when the fluid level switch (S5) is pressed.
15
the buzzer function is automatically reset for the
If ground is present when the switch is pressed, the
48
engine coolant overheat function. The buzzer cannot
indicator illuminates.
be turned off when the oil pressure is low.
ENGINE OIL LEVEL INDICATOR (H19)
The buzzer is reset by turning the key switch to OFF.
The buzzer will not sound more than once for the
Engine oil level switch (B7) is a normally open switch,
same problem unless it has been reset.
held closed with adequate oil level. The machine
ground is applied to controller terminal 7. The monitor
CONTROL SWITCHES AND INDICATORS
controller only checks the status of terminal 7 when
the fluid level switch (S5) is pressed. If ground is
WIPER SPEED SWITCH (S9)
present when the switch is pressed, the indicator
illuminates.
The wiper speed switch is used to select intermittent or
continuous windshield wiper operation. The monitor
ALTERNATOR VOLTAGE INDICATOR (H18)
controller provides ground switched outputs to the
windshield wiper circuit from controller terminals 24, 26
The alternator voltage indicator is controlled by the
27, and 28 based on the setting of the wiper speed
alternator excitation field voltage monitored by the
switch. If the windshield is open, a ground from
controller at terminal 42. When the alternator excitation
field voltage drops below 10 1.5 volts the indicator
windshield wiper enable switch S14 is allied to monitor
controller terminal 6, disabling the wiper speed switch.
illuminates. When the alternator excitation field voltage
goes above 13 1.5 volts the indicator goes out.
WINDSHIELD WASHER SWITCH (S15)
CHARGE AIR TEMPERATURE INDICATOR (H15)
When the windshield washer switch is pressed, the
monitor controller provides a ground switched output to
Charge air temperature switch (B12) is a normally
the windshield washer circuit from controller terminal
open switch that closes to machine ground when the
charge air temperature exceeds 100C (212F) . The
25.
machine ground is applied to controller terminal 44,
causing the indicator to illuminate.
Continued on next page
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