If the alternator is starting to go out on your vehicle, you may be able to notice some signs of it. If these warning signs are ignored, the problem can get larger and cause the vehicle trouble ranging from slow starts to a dead vehicle. The alternator is a vital part for the vehicle’s operation. The current it produces is used to power the vehicle’s accessories, like the headlights and radio. The alternator also helps to keep the battery fully charged, providing the power needed to start the vehicle.



The alternator warning light is linked to a computer system within the vehicle. It monitors the voltage output of the alternator as your vehicle is running. If the output from the alternator goes above or below the pre-set limit, then the light on the dashboard will illuminate. Once the output is within the proper range again, the light will turn off. Early stages of an alternator issue can cause the light to flicker, or come on for a second and then turn off. As more power is required because of headlights, windshield wipers, the radio, and other accessories, the alternator will need to work harder to maintain the necessary voltage.



You may notice that the headlights will start to dim or become extremely bright. Other accessories like power windows may also start to slowdown as well. This is caused by the alternator’s diminishing power that it produces. When it powers the headlights, they will become dimmer over time, and eventually be hardly noticeable.



When the alternator begins to fail, the battery will have to start to produce enough power for both. This can lead to the battery wearing out faster. While a battery going dead may be from variety of reasons, including age, the alternator may also cause it to loose its charge.



Electricity from the alternator is piped through large cables and small wires. Any issues that may occur within the wires, cables, or connects at either end, can reduce or stop the electricity from getting through. If this happens, you may also notice the smell of hot wires. Anytime you smell something out of the norm with your vehicle, bring it in to have it inspected before it becomes a larger issue.



You may hear a growling or whining noise before the alternator goes out. An accessory belt or a serpentine belt that is in conjunction with the crankshaft pulley powers the alternator. The alternator pulley spins two or three times faster than the crankshaft pulley to produce the necessary power. If the pulley is not aligned correctly with the belt, a growling or whining noise will start to occur.