JLG G5-18A Service Manual - Manual (Page 137)

9-17 G5-18A, 2505H, 25.5
Electrical System
9.6 CHARGING CIRCUIT
Before using a battery charger, an attempt can be made
to recharge the battery by jump-starting the machine.
(Refer to the appropriate Operation & Safety Manual.)
Allow the engine to run, which will enable the alternator to
charge the battery.
If the cab gauge shows an alternator issue, perform the
following checks:
1. Check the all battery cable connections at the
battery, and verify that they are clean and tight.
2. Check the external alternator wiring and
connections, and verify that they are in good
condition.
3. Check the fan belt condition and tension.
4. Verify that the alternator mounting hardware is tight.
5. Run the engine and check the alternator for noise. A
loose drive pulley, loose mounting hardware, worn or
dirty internal alternator bearings, a defective stator
or defective diodes can cause noise. Replace a worn
or defective alternator.
9.6.1 Alternator
a. Alternator 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 battery and engine covers. Allow the
engine to cool.
4. Properly disconnect the battery.
5. Label and disconnect the wires attached to the
alternator.
Note: Record how the alternator is installed to ensure
correct installation later.
6. Loosen the top mounting bolt (2), but don’t remove it
at this time. This will allow the alternator to swivel
during belt removal.
7. Loosen the belt tensioning adjustment bolt (3) at the
bottom of the alternator to loosen the fan drive belt.
8. Remove the fan drive belt from the alternator.
9. Remove the lower mounting capscrew securing the
alternator to the lower mounting hole on the engine.
10. While supporting the alternator with one hand,
remove the upper mounting hardware from the
upper alternator mount. Remove the alternator from
the machine.
b. Alternator Installation
1. Position the alternator and align with the upper
alternator mount on the engine bracket. Insert the
upper mounting hardware through the alternator
mount. DO NOT tighten completely at this time.
2. Align the lower alternator mount hole with the lower
mounting bracket on the engine, and insert the lower
mounting capscrew. Be sure to leave enough room
to attach the drive belt.
3. Attach the fan drive belt to the alternator.
4. Adjust the lower belt tensioning bolt to remove
excessive slack from the drive belt. Check for proper
fan belt deflection.
5. Reattach the previously labeled electrical wires to
the alternator.
6. Properly connect the battery.
7. Close and secure the battery and engine covers.
8. Remove the Do Not Operate Tags from both the
ignition key and the steering wheel.
MY8820
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