JLG 534D-10 - Manual (Page 162)

Electrical System
9.14 534D-9, 534D-10 & 544D
4. Start the engine, allow it to reach operating
temperature and observe the operator’s instrument
cluster for warning indication. If the sender 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.
Engine Oil Pressure Sender
a. Engine Oil Pressure Sender Removal
1. The engine oil pressure sender is located on the cab
firewall.
2. Remove the battery negative (-) cable at the negative
battery (-) terminal.
3. Remove the engine oil pressure sender wire from
the sender.
4. The sender is threaded into the mounting block.
Remove the sender.
b. Engine Oil Pressure Sender Inspection and
Replacement
Inspect the sender and wiring terminal for continuity.
Replace a defective or faulty sender with a new part.
c. Engine Oil Pressure Sender Installation and
Testing
1. Thread the engine oil pressure sender into the
mounting block snugly, then connect the sender wire
to the sender.
2. Connect the battery negative (-) cable at the negative
battery (-) terminal.
3. Check for proper oil level.
4. Start the engine, and observe the operator’s display
for warning indication. If the sender is not defective,
the problem could be elsewhere; possibly in a
shorted wire, improper-running engine, low oil,
obstructed or faulty oil pump, defective instrument
display.
Engine Oil Pressure Switch
a. Engine Oil Pressure Switch Removal
1. The engine oil pressure switch is located on the cab
firewall.
2. Remove the battery negative (-) cable at the negative
battery (-) terminal.
3. Remove and label the engine oil pressure switch
wires.
4. The switch is threaded into the mounting block.
Remove the switch.
b. Engine Oil Pressure Switch Inspection and
Replacement
Inspect the switch and the wiring terminals for continuity.
Replace a defective or faulty switch with a new part.
c. Engine Oil Pressure Switch Installation and
Testing
1. Thread the engine oil pressure switch into the
mounting block.
2. Connect the previously labeled wires to the switch.
3. Connect the battery negative (-) cable at the negative
battery (-) terminal.
4. Check for proper oil level.
5. Start the engine, and observe the operator’s display
for warning indication. If the switch is not defective,
the problem could be elsewhere; possibly in a
shorted wire, improper-running engine, low oil,
obstructed or faulty oil pump, defective instrument
display.
9.10.4 Fuel Level Sender
a. Fuel Level Indicator Testing
1. The fuel level sender wiring harness leads can be
accessed from the top of the fuel tank. Disconnect
the fuel level sender wiring harness leads. With the
help of an assistant, touch both harness leads
together.
2. From the operator’s 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’s instrument cluster. The
reading must be at the FULL mark.
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 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.