Top 10 Signs of Alternator Problems
Warning Light: If the alternator's output goes below or above a pre-set limit, then your car's warning dash light will come on. In most vehicles.
Dim Lights: A failing alternator could create electrical probems that could lead to erratic headlight issues, like frequent dimming or extreme brightness.
Flickering Lights: On the previous page, you learned that dim exterior and interior lights are common symptoms of alternator trouble.
A Dead Battery: A bad alternator can killing your car's battery, even if the battery wasn’t the problem to begin with.
Broken or Loose Connections: In this case, everything with your car's alternator seems to check out OK — no belt issues or other visible signs of trouble.
Bad Belts: A loose or bad belt can cause the alternator to run incorrectly, so a quick inspection of the belt can diagnose the problem.
Strange Sounds: If the sight of a failing alternator isn't obvious enough for you (and it's totally understandable if it's not), the sound might clue you in.
Strange Smells: Smell is the third sensory sign of alternator trouble, and it comes from the fact that your alternator is working way.
Slow Accessories: Trouble with power windows or power sunroofs could be a sign of a failing alternator.
Regular Stalling or Difficulty Starting: Difficulty starting your car or keeping it running is likely to crop up as one of the first symptoms of alternator trouble.