Lull 944E-42, Service Manual

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Electrical System
9.168 Model 644E-42/944E-42 Rev. 6/04
The negative (-) post of the battery is connected to the
starter ground stud (1). The engine is grounded through
ground strap (2) to the stud located on the firewall
crossmember (3).
The alternator includes an internal voltage regulator that
limits alternator voltage to a pre-set value and helps
prevent circuit overloads, power surges, etc. during peak-
voltage output.
Beyond inspecting the fan belt every 1,000 hours of
engine operation, there is no periodic maintenance
required for the charging circuit. When inspecting the fan
belt, also check the electrical wiring and connectors.
Under normal conditions the alternator will have no
problem keeping the battery charged. The only condition
in which the battery may cause a problem is when it has
been completely discharged for an extended period of
time. In this condition, the alternator may be unable to
recharge the battery, and a battery charger will be
required for recharging.
Before using a battery charger, an attempt can be made
to recharge the battery by jump starting the vehicle.
(Refer to the appropriate Owners/Operators Manual.)
Allow the engine to run, which enables the alternator to
charge the battery.
If the alternator charging warning indicator illuminates,
perform the following checks:
1. Check the battery cable connections at the
battery(ies) 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. (Refer to
appropriate Owners/Operators Manual for general
information.)
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.
6. For additional information on the charging circuit
refer to Section 9.8.28, “Charging Circuit &
Troubleshooting.”
MU6550
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WARNING:
DO NOT charge a frozen
battery. A frozen battery may explode and
cause serious personal injury. Allow the
battery to thaw before “slave starting” the
vehicle or connecting a battery charger.
CAUTION:
Before performing ANY
welding on vehicle, disconnect the negative (-)
battery cable at the negative (-) battery
terminal. Failure to remove the negative (-)
battery cable will result in damage to vehicle
electronic systems.