GROUND FORCE 717H01, Operation & Maintenance Manual, Page: 43 / 57

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WATER TRUCK TROUBLESHOOTING
PROBLEM CAUSES SOLUTIONS
ELECTRICAL
W
at
er pum
p will no
t engage.
The low-level shut-off feature
has turned off the pump.
Check the Water Control System display screen. If the wa-
ter pump icon is red, the low-level shut-off is engaged.
Add water to the tank.
The low-level float switch
has malfunctioned, or can't
communicate with the micro-
controller.
Test the wiring by placing a jumper wire across the con-
nector going to the float switch. If the pump now starts, re -
place the low-level float. If it still does not work, check the
wiring from low-level float to the micro. Repair as needed.
The low-level float is installed in
the wrong position.
Check the timing of the float to make sure the float is in -
stalled in the correct direction. The float switch should be
installed normally open, with the float pointing down.
The micro-controller has failed. Call Ground Force and request the Technical Communica-
tor for assistance with replacing the micro-controller.
The hoist or diverter valve coil
has no power.
The fuse is blown. Replace with the correct size fuse.
Check for a short in the wiring, broken wire or bad connec-
tion. Repair or replace the wiring or connector as needed.
The wire is connected to the
wrong coil(s) on the hoist valve
or the diverter valve.
Refer to schematics and correct the wiring on hoist or
diverter valve coils.
Div
er
ter v
alv
e coil or hoist v
alv
e
coil has po
w
er
, but w
at
er pum
p will
no
t engage.
The coil or solenoid is bad. Test the solenoid for magnetism. If the solenoid is magne-
tized, but will not activate the valve, then the solenoid may
be bad. If the solenoid is not magnetized, the coil may be
bad.
Rigid frame chassis only:
Hydraulic back-pressure
at diverter valve is low or
nonexistent.
Verify that a check valve is installed per print in the return
line leaving the diverter valve.
Verify the check valve is functioning properly and is not
stuck open.
43
TROUBLESHOOTING