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What's Wrong If My Battery Or Charging System Light Comes On?

Understanding The Battery Indicator Light

The charging system light or battery indicator light shouldn't be ignored.. Whenever this indicator light turns on, it means that the vehicle is relying solely on the stored battery power to continue to power all of its electronic components. Unfortunately, this means the car is limited in how far it can travel before the car dies due to lack of electrical power. Most vehicles will display the warning light in one of three ways:

  • The light may be red or amber and displays the "CHG" or "ALT" icons.
  • The indicator light is red and displays the "BATT" when the key is in the ignition and the engine is off.
  • Most commonly, there's a red icon that represents a car battery.


Auto Repair Tempe Alternator

Before the 1990's, the charging systems in vehicles relied on a voltage regulator near or inside the alternator itself to function properly. The light was attached to the battery and whenever the vehicle started, the light was grounded by the alternator. Whenever the engine was started and the alternator produced electricity, the voltage would recirculate through the entire vehicle's electrical system. The charging system relied on two sources of voltage in order to turn the light off. If the voltage was imbalanced in any form, the battery light would illuminate.

As advancements in car technology became more sophisticated, the charging system was connected to the power train computer. This adaptation would allow for more accurate readings of the voltage and would prove to be beneficial in the long run. The modern computer systems powering our vehicles today can now provide more accurate readings of the voltage circulating throughout the electrical system because of this new change. In these modern vehicles, the battery lightwill illuminate only when the power train computer detects an unusual difference in the default system voltage and the present system voltage.

How To Do A Simple Charging System Check

Upon placing the key in the ignition and cycling between the off, run, and start positions, the charging system will administer a self check. When you start the engine, the indicator light should remain on from 1-2 seconds and then automatically shut off. If the light turns off after the 2 seconds, that means the charging system is functioning properly. If the indicator light remains on, or turns off and on randomly while the vehicle is running, there's a problem with the charging system. An alternative problem might exist if the charging light never came on at all during this simple test. It could mean the charging system and or light needs repairs.

How and When To Seek Repairs

Because your vehicle relies on a reliable supply of electricity in order to power all the electrical components of the car, this isn't a problem that will simply resolve itself over time. If at all possible, bring your vehicle into our repair shop to resolve the matter. If the warning light should come on while you're driving at night, find a nearby mechanical shop before the engine dies.

You can buy yourself more time by turning off all un-necessary electrical devices you're not using such as the air conditioner/heater, the radio, etc. The vehicle may only have a few miles left before the engine dies. If you can, pull over to a safely lit area and call a towing company. If the battery light illuminates while you're driving during the day, you have more time to come up with a solution because you're not relying so much on electrical draining components such as your headlights. However, you should still turn off or refrain from electrical devices you're not using. If possible pull your car into our repair shop as soon as possible.

Alternatively, should the battery light be accompanied by the temperature light, it's crucial you cease all activity with the car. The belt that powers the alternator is often shared with the water pump. Should the water pump fail to function, the engine will overheat resulting in major damage and expensive repairs.


Regardless of the problem, if you experience any of these problems give Elite Auto Repair a call and we'll come to your assistance and get you back on the road ASAP!

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