JLG G12-55A AccuPlace Service Manual - Manual (Page 142)

Electrical System
9.24 G10-55A & G12-55A AccuPlace
9.8 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 (2) to charge the battery.
If the engine alternator charging warning indicator
illuminates, perform the following checks:
1. Check 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. 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.
9.8.1 Alternator
a. Alternator Removal
1. Open the engine cover. Allow the system fluids to
cool.
2. Disconnect the battery negative (-) cable at the
battery negative (-) terminal.
3. Install a drive ratchet into the square hole in the
serpentine belt tensioner bracket.
4. While lifting the automatic belt tensioner away from
the belt, remove the fan serpentine belt.
Note: Record how the alternator is installed to ensure
correct installation later.
5. Label and disconnect the wire leads attached to the
alternator.
6. Remove the lower mounting capscrew securing the
alternator to the lower mounting hole on the engine.
7. While supporting the alternator with one hand,
remove the upper (longer) 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 (longer) mounting hardware through the
alternator mount. Thread the longer capscrew into
the alternator front 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. Tighten the lower capscrew and
upper capscrew securely.
3. Place a drive ratchet into the square hole on the
serpentine belt tensioner bracket. Apply pressure
against the tensioner bracket and route the
serpentine belt onto the alternator and engine
pulleys. Release and check the tensioner pulley to
verify that it is pivoting freely in order to provide the
proper tension on the belt. Check for proper belt
alignment. (Refer to the appropriate Operation &
Safety Manual.)
4. Connect the previously labeled wire leads to the
alternator.
5. Connect the battery negative (-) cable to the battery
negative (-) terminal.
6. Close and secure the engine cover.
MY0370
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