Charging System - General Information
SECTION : 414-00 Charging System - General
Description and Principles of Operation ...............................................................................414-00-1
01/2006 2006.0 BF Falcon
Charging System - General Information
4. Battery Connections. The battery must never be
Description and Principles of
disconnected while the engine is running or
damage may occur to the rectifier and/or control
box semi-conductor devices. For this reason the
The charging system consists of an alternator,
practice of using a slave battery to start the
alternator regulator, battery, charge indicator light and
engine, then reconnecting the original battery
the necessary wiring to connect to the components.
whilst the engine is running must not be
All vehicles are equipped with a non-adjustable
attempted. It is likewise inadvisable to break or
integral electronic regulator. Six cylinder vehicles use
make any other connections in the alternator
a Mitsubishi alternator and eight cylinder vehicles use
circuit while the engine is running.
a Visteon alternator. These alternators are essentially
5. Alternator Main Output Cable
the same internally but the exterior casing varies.
Both the Mitsubishi (6 Cyl.) and Visteon (8 Cyl.)
The cable connecting the alternator and the
alternators are three phase alternating current (AC)
battery is 'live' even when the engine is not
generators with integrally mounted diodes that convert
running. Care must be taken not to earth this
the AC into direct current (DC) suitable for charging
live cable if it should ever be removed, or
the battery.
damage to the cable will occur.
Charging system troubles such as low alternator
The alternator must never be run with the
output, no alternator output (indicated by the indicator
main output cable disconnected either at the
light being on while the engine is running), or
alternator or battery end while the field
alternator output voltage too high, require testing of
remains energised or the rectifiers may be
both the alternator and the alternator regulator.
Alternator regulator failures are usually not recognized
6. Arc Welding. The possibility of damage to the
except by the direct effect on the alternator output,
semiconductor devices during arc welding
and, hence, consequently battery discharge. As the
operations on a vehicle is very slight. However, it
regulator is the control valve for the alternator, it acts
is a worthwhile precaution to isolate the control
to protect the battery by preventing excessive voltage
box and alternator by disconnecting their wiring
connectors prior to carrying out any arc welding
on the vehicles.
Discharge of the battery to ground through the
alternator is prevented by the diodes of the alternator
Removal notes
which permit current flow in one direction (to the
battery) only. A discharged battery is not always due
7. Ensure battery shroud is not damaged or
to charging system defects. Excessive use of lights
dislodged during battery removal.
and accessories while the engine is either off or
8. Use a universal battery removal tool to enable
running at low idle; corroded battery cables and
removal of battery with shroud in situ.
connectors; low acid level in the battery; or prolonged
9. Ensure shroud and venting pipes are installed
disuse of the battery, which would permit
self-discharge; are all possible reasons which should
be considered when a battery is run down or low in
The procedures which follow will assist in a logical
sequence of pinpointing specific troubles.
Always determine the cause of failure as well as
making the repair.
1. Polarity and connections. The alternator is for
use on negative earth electrical systems only.
Polarity cannot be reversed by 'flashing' the field
terminals as with the dynamo. Any attempt to do
so will damage the alternator.
2. Refitting Vehicle Battery. Reversed battery
connections will damage the alternator rectifiers.
When refitting, first fit the positive (+) connector to
the battery positive (+) terminal. Then fit the
negative (-) connector to the negative (-) battery
3. Battery Charging. First disconnect the battery
negative cable, thus isolating the alternator from
the battery and external charging equipment.
G34560 en
01/2006 2006.0 BF Falcon