Alternator; Checking No-Load Adjustment Voltage; Checking Output - Ford TRADER Workshop Manual

G
CHARGING SYSTEM
ALTERNATOR
Caution
• Be sure the battery connections are not reversed, because this will damage the rectifier.
• Do not use high-voltage testers such as a megger, because they will damage the rectifier.
• Remember that battery voltage is always applied to the alternator B terminal.
• Do not ground the L terminal while the engine is running.
• Do not start the engine while the connector is disconnected from the Land
S
terminals.
9TGOGH)09
AMMETER
A
ENGINE
s~
B TERMINAL
9TGOG1·011
G-6
Inspection (On-vehicle)
Checking no-load adjustment voltage
1 . Check to be sure that the battery is fully charged.
2. Connect an ammeter and a voltmeter as shown in the figure.
Be sure that the voltmeter reading is OV.
3. Turn the ignition key to ON, and then check to be sure that
the voltmeter reading is significantly lower than the battery
voltage (0.5-4V). If the voltmeter reading is the same as
the battery voltage, there may
be
a malfunction in the
al-
ternator.
4. Short circuit the terminals of the ammeter, and then start
the engine. After starting, discontinue the short circuiting.
Caution
• Be careful, when starting the motor, that the cur-
rent of the starter doesn't flow to the ammeter.
5. Under no-load conditions, increase the alternator speed to
5,000
rpm (engine speed of
2,000-2,500
rpm).
6. Read the indication shown by the voltmeter and the
ammeter.
Ammeter: SA or less
Voltmeter (adjustment voltage):
14.4 ± O.3V (at 20°C (68°F»
CHECKING OUTPUT
1. Disconnect the negative battery cable.
2. Connect an ammeter and a voltmeter as shown in the figure.
3. Connect the negative battery cable.
4. Start the engine.
5. Apply a load by turning on the headlights.
6. Gradually increase the engine speed, and read the output
current.
If the voltage is higher than the battery voltage and there
is an output current, there is no problem.