Bad Alternator:
1. Dimming or Flickering Lights: If your car's lights are dimming or flickering while driving, especially at lower RPMs, this could be a sign of a failing alternator.
2. Battery Warning Light: Check your dashboard for any warning lights, particularly the battery light. If the battery light stays illuminated while driving, it may indicate an issue with the alternator.
3. Electrical Component Issues: Difficulty in starting the vehicle, frequent battery recharging, or malfunctioning of various electrical components (such as power windows, fan, radio) can point towards an alternator problem.
4. Growling or Whining Noises: Unusual groaning, grinding, or high-pitched squealing noises can come from a faulty alternator.
5. Voltage Issues: Using a voltmeter, measure the voltage of the battery with the engine running. A value significantly below or above the standard (for most car batteries, it's around 14 volts) may suggest alternator issues.
Bad Car Battery:
1. Difficulty Starting: If your car has trouble starting in the morning or cranks slowly, the battery may not be receiving enough charge or might be nearing the end of its lifespan.
2. Swollen Battery Case: Look for any swelling or bulging on the battery case. Swelling usually indicates excessive or rapid gas buildup, a sign of internal damage.
3. Corrosion on Terminals: Check the battery terminals and cables for corrosion, rust, or white residue. These can disrupt the electrical connections between the battery and the alternator.
4. Leaking Battery: If you detect a strong acidic odor near the battery compartment, this may be a sign of leakage—another consequence of internal damage and impending battery failure.
Note: It can sometimes be challenging to determine whether the cause lies with the alternator or the battery alone. While some of the symptoms overlap, you might need some multimeter testing at an auto service center for a definitive diagnosis.
