JLG 4017PS Service Manual - Manual (Page 195)

9-37 3706PS, 3707PS, 4014PS, 4017PS, 33.7, 37.6, 37.7
Electrical System
the fuel level sender wiring harness leads. With the
help of an assistant, touch both harness leads
together.
2. From the operator cab, have the assistant turn the
ignition key switch to the RUN position. DO NOT
start the engine. Observe the fuel level indicator
needle on the operator instrument cluster. The
reading must be at the FULL mark.
3. Turn the ignition key switch to the OFF position. The
fuel level indicator needle should return to the
EMPTY position.
b. Fuel Level Circuit Tests
If the fuel level sender (2) is suspected of giving a false
reading, perform the following checks:
1. If the fuel level indicator needle does not move,
check the fuel tank for fuel.
2. Check for loose or defective wiring, faulty ground
connections, and corrosion on the fuel tank sender
and wiring lead.
3. If the fuel level indicator needle does not move after
the ignition key switch is turned to the RUN position,
use a test lamp to determine whether current is
flowing from the ignition switch to the fuel level
sender.
4. If the fuel level indicator does not move and a faulty
or defective fuel level sender in the fuel tank has
been ruled out, and in addition, wiring and
connectors have been checked and ruled out, the
fuel level indicator is defective and must be
replaced.
5. Check that the ignition terminal has current and that
the fuse in the fuse panel is not blown.
6. Check for broken, shorted, frayed, disconnected or
damaged wiring between the fuel level indicator
wiring at the cab, fuse and relay panel, ignition key
switch, and from the fuel level sender on the fuel
tank through the wiring in the cab.
7. Check the fuel level sender. A defective fuel level
sender in the fuel tank may also prevent the fuel
level indicator from moving. Refer to Section 9.8,
“Electrical System Schematics,” for further
information.
9.12.6 Front and Rear Axle Steering Sensors
The sensors used on each axle allow the steering to be
changed to one of three different settings. The sensors
will not allow the change to be completed unless both
axles are in the central location.
Each sensor is mounted in the center of each steer
cylinder.
9.12.7 Boom Angle Sensor
The boom angle sensor is located at the top left inside
rear of the boom.
a. Boom Angle Sensor Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower the boom,
place the transmission control lever in (N)
NEUTRAL, engage the park brake and shut the
engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
3. Open the engine cover. Allow the engine to cool.
4. Properly disconnect the battery.
MAM0590
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