How To Test Alternator Output. After watching this video you will be able to safety test alternator voltage output. Connect the carbon pile to the battery.
If its below that charge the battery with a battery charger before you conduct the test again. The proper test other than by actually measuring the amperage which is not easy with an alternator if there is no permanent ammeter installed and risks damage to the alternator momentary disconnection on load will blow the diodes instantly is to load a charged battery at about 10 amps for 5 minutes 5 amps for 10 minutes will be the same. Use a multimeter and set it to read amperes.
One of the easiest ways to test the integrity of your alternator is by using a very simple device called a voltmeter.
Check that wiring to the alternator is not broken or disconnected. Testing Alternator with Multimeter With the engine on. Zero out the ammeter connect as above and perform the test with the vehicle off. Then start the engine and check for increased voltage readings.
