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2. Turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Disconnect the alternator output wire from the alternator "B" terminal.
5. Connect a DC ammeter (0 to 150A) in series between the "B" terminal and the disconnected output wire. Be sure
to connect the (-) lead wire of the ammeter to the disconnected output wire.
Tighten each connection securely, as a heavy current will flow. Do not rely on clips.
6. Connect a voltmeter (0 to 20V) between the "B" terminal and ground. Connect the (+) lead wire to the alternator "B"
terminal and (-) lead wire to a good ground.
7. Attach an engine tachometer and connect the battery ground cable.
8. Leave the engine hood open.
TEST
1. Check to see that the voltmeter reads as the same value as the battery voltage. If the voltmeter reads 0V, and the
open circuit in the wire between alternator "B" terminal and battery (-) terminal or poor grounding is suspected.
2. Start the engine and turn on the headlamps.
3. Set the headlamps to high beam and the heater blower switch to HIGH, quickly increase the engine speed to 2,500
rpm and read the maximum output current value indicated by the ammeter.
After the engine start up, the charging current quickly drops.
Therefore, the above operation must be done quickly to read the maximum current value correctly.
RESULT
1. The ammeter reading must be higher than the limit value. If it is lower but the alternator output wire is in good
condition, remove the alternator from the vehicle and test it.
Limit value : 70％ of the rated current
• The nominal output current value is shown on the nameplate affixed to the alternator body.
• The output current value changes with the electrical load and the temperature of the alternator itself.
Therefore, the nominal output current may not be obtained. If such is the case, keep the headlamps on the
cause discharge of the battery, or use the lights of another vehicle to increase the electrical load.
The nominal output current may not be obtained if the temperature of the alternator itself or ambient
temperature is too high.
In such a case, reduce the temperature before testing again.
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