JLG G12-55A AccuPlace Service Manual - Manual (Page 150)

Electrical System
9.32 G10-55A & G12-55A AccuPlace
9.11.10 Engine Coolant Temperature
Sender / Switch
a. Engine Coolant Temperature Sender 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 system fluids to
cool.
4. Disconnect the battery negative (-) cable from the
battery negative (-) terminal. Unplug the engine
coolant temperature sender /switch connector from
the wiring harness connector.
5. Unplug the engine coolant temperature sender
connector from the wiring harness connector.
6. The engine coolant temperature sender (1) is
threaded into the engine block. Remove the sender.
b. Engine Coolant Temperature Sender / Switch
Inspection and Replacement
Inspect the sender/switch and the wiring harness
connector terminals for continuity. Replace a defective or
faulty sender with a new part.
c. Engine Coolant Temperature Sender Installation
and Testing
1. Thread the engine coolant temperature sender into
the engine block snugly, then connect the sender
connector to the wiring harness connector.
2. Connect the battery negative (-) cable to the battery
negative (-) terminal.
3. Check for proper coolant level.
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.
5. Close and secure the engine cover.
9.11.11 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.
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:
MY2830
1
MAP0440
2