JLG 4017RS Service Manual - Manual (Page 173)

9-21 3614RS, 4017RS
Electrical System
5. Check for proper coolant level.
6. Start engine, allow it to reach operating temperature
and observe operator instrument cluster for warning
indication. If sensor is not defective, the problem could
be elsewhere; possibly in a shorted wire, improper-
running engine, improper or low coolant, obstructed or
faulty radiator, coolant pump, loose fan belt, defective
instrument display, etc.
7. Close and secure engine cover.
8. Remove Do Not Operate Tag from ignition key switch
and steering wheel.
9.8.5 Fuel Level Sender
a. Fuel Level Indicator Testing
1. Fuel level sender wiring harness leads can be accessed
from lowered fuel tank. Refer to Section 7.6.2, “Fuel
Tank,” for detailed fuel tank removal and installation.
2. Disconnect fuel level sender wiring harness leads.
3. With the help of an assistant, touch both harness leads
together.
4. From operator cab, have assistant turn ignition key
switch to RUN position. DO NOT start engine. Observe
fuel level indicator needle on operator instrument
cluster. Reading must be at FULL mark.
5. Turn ignition key switch to OFF position. Fuel level
indicator needle should return to EMPTY position.
b. Fuel Level Circuit Tests
If fuel level sender (2) is suspected of giving a false reading,
perform following checks:
1. If fuel level indicator needle does not move, check fuel
tank for fuel.
2. Check for loose or defective wiring, faulty ground
connections, and corrosion on fuel tank sender and
wiring lead.
3. If fuel level indicator needle does not move after
ignition key switch is turned to RUN position, use a test
lamp to determine whether current is flowing from
ignition switch to fuel level sender.
4. If fuel level indicator does not move and a faulty or
defective fuel level sender in fuel tank has been ruled
out, and in addition, wiring and connectors have been
checked and ruled out, fuel level indicator is defective
and must be replaced.
5. Check that ignition terminal has current and that fuse in
fuse panel is not blown.
6. Check for broken, shorted, frayed, disconnected or
damaged wiring between fuel level indicator wiring at
cab, fuse and relay panel, ignition key switch, and from
fuel level sender on fuel tank through wiring in the cab.
7. Check fuel level sender. A defective fuel level sender in
fuel tank may also prevent fuel level indicator from
moving. Refer to Section 9.5, “Electrical System
Schematics,” for further information.
9.8.6 Boom Retract Sensor
The boom retract sensor is located inside rear of boom.
a. Boom Retract Sensor Testing
1. Ensure boom is fully retracted and verify using cab
display that boom retract switch is activated.
2. Extend the boom 100mm and verify using cab display
that boom retract switch is deactivated.
If boom retract sensor is suspected of giving a false reading,
perform following checks:
3. Check for loose or defective wiring, faulty ground
connections, and corrosion on boom retract sensor and
wiring lead.
4. Check that ignition terminal has current and that fuse in
fuse panel is not blown.
5. Check for broken, shorted, frayed, disconnected or
damaged wiring between display wiring at cab, fuse
and relay panel, ignition key switch, and from boom
retract sensor on boom through wiring in cab.
b. Boom Retract Sensor Removal
1. Park machine on a firm, level surface, level machine,
fully retract boom, lower boom, place transmission in
(N) NEUTRAL, engage park brake and shut engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and steering wheel.
3. Open engine cover. Allow system fluids to cool.
4. Properly disconnect battery.