An alternator is a type of electric generator used in modern automobiles to charge the battery and to power the electrical system when its engine is running. Until the 1960s, automobiles used …

Mar 4, 2025 · Learn how your car's alternator powers electrical components and charges the battery. Discover how it works, signs of a bad alternator, and when to get service.

Alternators are driven by the engine's serpentine belt or V belt to generate power for the radio, lighting, and on-board computer systems on your vehicle, but also provide power to the battery …

May 9, 2022 · An alternator is a generator of electric power in a car and is a major component of the vehicle's charging system. All cars with an internal combustion engine except for some …

Dec 23, 2025 · Diagnose a failing alternator. Learn the key warning signs, step-by-step voltage testing methods, and the critical timing for replacement.

Find an alternator that fits your car and delivers the same performance as original equipment, or better. We carry long lasting replacements, like Duralast Gold alternators that come with a …

Nov 18, 2025 · alternator, Source of direct electric current in modern vehicles for ignition, lights, fans, and other uses. The electric power is generated by an alternator mechanically coupled to …

Get an estimate today and take your vehicle to your local NAPA Auto Care center for alternator repair or replacement service by an ASE-certified technician.

Feb 24, 2025 · If your car or truck won't hold a charge, you may need a new alternator. Learn alternator replacement, how to test it and find the best deal.

In principle, any AC electrical generator can be called an alternator, but usually, the term refers to small rotating machines driven by automotive and other internal combustion engines. An …