JLG G5-18A Service Manual - Manual (Page 122)

Electrical System
9.22 G5-18A/2505
3. Align the ignition switch so that when it is in the OFF
position, the key slot is positioned vertically (straight
up and down). Install the hex nut securing the
ignition switch to the dash. DO NOT overtighten.
4. Install the lower dash panel.
5. Connect the battery negative (-) cable to the battery
negative (-) terminal.
6. Close and secure the battery cover.
9.11.2 Dash Switches
a. Switch Removal
1. Open the battery cover.
2. Disconnect the battery negative (-) cable at the
battery negative (-) terminal.
3. Pull the frame out of the dash, disconnect the
harness connector to the switch in question and
push the switch out of the frame.
b. Disassembly
DO NOT disassemble the dash switch. Replace a
defective switch with a new part.
c. Inspection and Replacement
Inspect the switch terminals for continuity in both the
engaged and disengaged positions. Replace a defective
or faulty switch with a new switch.
d. Switch Installation
1. Connect the switch to the cab harness connector.
2. Position the switch over the rectangular switch bezel
and snap into position.
3. Replace the frame into the dash.
4. Connect the battery negative (-) cable to the battery
negative (-) terminal.
5. Start the machine and check the replaced switch for
proper function.
6. Close and secure the battery cover.
9.11.3 Fuel Level Indicator and 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.
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 indicator 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 or 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 the instrument
cluster 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. The resistance of the
fuel level sender is 31 ohms for a full tank of fuel,
101 ohms for 1/2 tank and 255 ohms for an empty
tank. A defective fuel level sender in the fuel tank
may also prevent the fuel level indicator from
moving.
9.11.4 Hourmeter
The hourmeter is a non-repairable instrument that
records hours of machine engine operation in tenth of an
hour increments and is located in the instrument cluster.
The hourmeter is an analog device, similar to an
odometer, and will display 99,999.9 hours before
resetting to zero.