Your car naturally produces energy to power its electrical components while you're driving instead of draining the battery, and it's the alternator's job to transform that raw energy into electricity and direct it around your engine and accessory parts. A dead alternator will leave you stranded in a parking lot or on the side of the road, so paying close attention to it is a good idea. Get your alternator checked by a mechanic immediately if you notice any of these early warning signs of trouble.
Noticing your headlights getting dimmer and brighter randomly or as you switch power-draining options like the air conditioning on and off? This is likely due to an alternator that is struggling to perform its job. The lack of power can also cause them to dim evenly and slowly as the alternator gradually produces less and less power.
An alternator will cause your car to refuse to start, yet respond just fine after a jump start. A dead battery or starter won't necessary respond to jump starting, while an aging alternator just causes your battery to run down. If the car jump starts but runs down again immediately or after a few minutes, it's a sign your alternator is no longer providing power in place of the battery. Even an occasional need to jump start your car means your alternator is likely getting old.
As power levels fluctuate while the alternator struggles to provide a steady flow of electricity, you may notice your A/C alternating between cold and tepid blasts of air. Other signs include dim or blinking lights on the dashboard, low pitched or distorted alarm and warning noises, and GPS units and other accessories that refuse to start or which restart regularly as you drive.
Sometimes the alternator starts making noise under the hood shortly before more serious signs of alternator problems set in. If you listen carefully after starting your car, you may notice a rumbling or rattling noise that is only just a little louder than the rest of the engine noise. Have a mechanic use an engine stethoscope to determine if the noise is coming from the alternator's bearings getting worn down or drying up.
Finally, get the alternator inspected whenever you need to get your battery replaced more than every three to six years. An alternator that is still working but loosing efficiency can wear out a battery prematurely, resulting in wasted money on unnecessary replacements.
For more information, contact local professionals like Professional Automotive.