The most common way to notice an issue with the vehicle is by any warning lights that might illuminate on the dashboard. If the light that is shaped like a battery or one that says “ALT” illuminates, it could mean there is an issue with the alternator of the vehicle. This light will not always mean there is an issue with the battery
Another way to be aware of a poor alternator is if you notice the lights on the vehicle have become dimmer. This is because the alternator supplies the electrical needs for the vehicle. When it starts to fail, some of the electrical components will decrease in effectiveness as well. This can include the lights, windshield wipers, power windows, and other electrical parts.
Between visits, make sure you are inspecting the vehicle, and be aware of any issues that might be out of the norm for it. This could include a belt that is loose or hanging. A visual inspection can help ensure all the parts are working, as they should be. Also be aware of any sounds you might hear. This can include a growling or whining noise coming from the alternator. The accessory belt or serpentine belt will help to drive the alternator. If it is not in correct alignment, the bearings could start to cause an issue and make odd noises that will indicate an issue. When you notice an issue at the first sign, you can help prevent further damage and wear and tear by bringing it in to be inspected.