1. Connect the red lead of the multimeter to the positive terminal on the battery and the black lead to the negative terminal.
2. Turn on the engine and let it run for a few minutes.
3. Set the multimeter to the "Volts" setting.
4. Touch the positive lead of the multimeter to the output terminal on the alternator.
5. The multimeter should display the voltage output of the alternator.
Normal Voltage Readings for a Car Alternator
The voltage output of a healthy alternator should be between 13.5 and 14.5 volts at idle. If the voltage is lower than 13.5 volts, the alternator may not be charging the battery properly. If the voltage is higher than 14.5 volts, the alternator may be overcharging the battery, which can damage the battery and other electrical components in the car.
If you suspect that your alternator is not working properly, you can have it tested by a qualified technician.
