Charging System Diagnosis And Testing; Alternator Operation; Battery Testing - Ford VSG-411 Service Manual

4-01
Charging System
4-01
PART
4
Charging System
COMPONENT INDEX
Page
COMPONENT INDEX Page
DESCRIPTION AND OPERATION
ADJUSTMENTS
Alternator (Bosch) . . . . . . . . . . . . . . . . . . . . . .
4-01 Belt Adjustments . . . . . . . . . . . . . . . . . . . .
4-04
DIAGNOSING AND TESTING
REMOVAL AND INSTALLATION . . . . . . . . . .
4-04
Charging System Tests . . . . . . . . . . . . . . . 4-02
OVERHAUL . . . . . . . . . . . . . . - , . . . . . . . . .
4-04
Bench Tests . . . . . . . . . . . . . . . , . . . . . . . . 4-03
I
DESCRIPTION AND OPERATION
ALTERNATOR
The Alternator charging system is a negative ground system,
and consists of an alternator, a regulator, a charge indicator, a
storage battery, and associated wiring.
The alternator is belt driven from the engine. Current is sup-
plied from the alternator-regulator system to the rotating field of
the alternator through two brushes to two slip rings.
The alternator produces power in the form of alternating cur-
rent. The alternating current is rectified to direct current by six
diodes. The alternator regulator automatically adjusts the alter-
nator field current to maintain the alternator output voltage within
prescribed limits to correctly charge the battery. The unit has an
integral voltage regulator mounted on the rear housing.
DIAGNOSIS AND TESTING
PRELIMINARY INFORMATION
Before performing charging system tests on the engine, note the
complaint such as: slow cranking, battery dead or using an exces-
sive amount of water, top of battery wet, ammeter shows charge at
all times and/or no charge, alternator warning lamp does not come
on and/or never goes out, voltmeter shows above or below open
circuit nominal voltage. This information will aid in isolating the
part of the system causing the symptom.
Next, visually inspect as follows:
1. Check battery posts and battery cable terminals for clean and
tight connections. Remove the battery cables (if corroded),
clean and install them securely.
2. Check for clean and tight wiring connections at the alternator,
regulator and engine. Inspect for evidence of arcing.
3. Check the alternator belt tension using belt tension gauge
T63L-8620-A, Model 210019 or equivalent and tighten to
specification (if necessary).
ISOLATING THE PROBLEM
Battery, starting system, and light systems problems can be
caused by poor charging system performance. It is also possible to
suspect the charging system because of an overload in another area
of the electrical system.
To avoid guesswork, it is necessary to isolate the battery, the
charging system, and the electrical circuits to correctly identify
the area where the difficulty lies. The best method to do this is to
check the battery first before any electrical system diagnosis. The
battery must be in proper state of charge. The battery must be
operating properly before the other areas of the electrical system
can perform normally.
BAlTEpY TESTING
WARNING: Keep batteries out of reach of children. Batteries
contain sulfuric acid. Avoid contact with skin, eyes or
clothing. Also, shield your eyes when working near the battery
to protect against possible splashing of the acid solution. In
case of acid contact with skin, eyes, or clothing, flush immedi-
ately with water for a minimum of 15 minutes. If acid is
swallowed, drink large quantities of milk or water, followed
by milk of magnesia, a beaten egg or vegetable oil. Call a
physician immediately.
Hydrogen and oxygen gases are produced during normal
battery operation. This gas mixture can explode if flames,
sparks or lighted tobacco are brought near the battery. When
charging or using a battery in an enclosed space, always
provide ventilation and shield your eyes.
WARNING: Batteries are heavy, weighing 30 lbs. or more.
Lift them with your legs rather than your back to prevent
muscle strains, and be careful not to drop them (possible
breakage) or to spill the contents (sulfuric acid).
CAUTION: X&volt starting motors can be damaged beyond
repair if connected to a 24.volt power supply (two 12.volt
batteries in series, or a 24-volt motor-generator set), even
when cranking loads are relatively light. Extensive starting
motor damage is more likely if the starter is connected to a 241
volt supply while being subjected to prolonged heavy cranking
loads such as attempting to start an engine in subzero
temperature.
Tests are made on a battery to determine the state of charge and
also its capacity or ability to crank an engine. The ultimate result
of these tests is to show that the battery is good, needs recharging,
or must be replaced.
Before attempting to test a battery, it is important to give it a
thorough examination to determine if it has been damaged. Re-
move battery cable clamps, negative ( - ) terminal first. Check for
dirty or corroded connections and loose battery posts. Remove
hold downs and heat shields and inspect for broken or cracked case
or cover. If worn or damaged, loose or broken post, or cracked
case or cover, replace battery.
The battery capacity test should be run next to remove any
surface charge prior to determining state of charge of a mainte-
nance free battery.