Here are the steps to test your alternator:
1. Use a voltmeter to check your alternator. Rev your engine to 2000 RPM, keep the engine running, and test the battery with the voltmeter.
2. If your voltage goes from ~12.2 V to ~13-14.5 V, your alternator is doing well.
3. If your V stays the same or decreases, that's a bad sign.
4. Prepare your multimeter by setting it to voltage and ensuring it’s adjusted to 20 DC volts.
5. Touch the probes to your battery terminals.
6. Do not start the car yet!
7. Check the reading.
8. If the alternator tests fine, you can move on to other possible causes of the problem.
