Menu

When your car’s electrical system seems to be suffering problems, it can be concerning. You could experience a dead battery or glitchy electronics that take your attention away from the road. While there can be plenty of causes for these troubles, one potential point of failure is the alternator. This small yet powerful generating station is supposed to provide electricity for your car, and it needs to be fixed if there’s a problem.  

Some car repairs are minor, costing under $50 while major repairs can be thousands of dollars. An alternator is on the lower end of the scale and, depending on several factors, will cost somewhere between $100 and $1,000.  

Factors Affecting the Alternator Price 

New alternators might all look roughly the same, but differences between them will affect their price. They include:  

  • The year, make, model, and engine size. Only an exact match for your car’s needs will do, so always shop for parts like the alternator taking its specs into consideration.  
  • The amperage. Smaller alternators that don’t need to generate as much electricity for the car tend to have less high-value material content like copper used in the windings. Thus manufacturing costs are lower. It isn’t always the case, though.  
  • Its mounting style. Since the alternator needs to fit perfectly, you can’t choose a low-cost alternator intended for a different car. It won’t work.  
  • The types of electrical connections. Alternators for older cars that are considered 1-wire alternators often are lower priced, while 3-wire alternators tend to be more expensive. 
  • The new part’s warranty. Choosing a new part with 1 year of warranty compared to a similar part with a lifetime warranty will, expectedly, cost you more money initially.  

The Role of the Alternator 

How an alternator works cutaway

Cars today require a surprising amount of power. Not only are there obvious systems that need power like the radio, power windows, door locks, sunroof, and heated seats but there are modules and sensors all around as well. As an example, the anti-lock brakes usually have a wheel speed sensor at every wheel, an anti-lock brake control module, an ABS pump, and other related parts that all need constant access to power.  

The alternator takes power from the battery and amplifies as an electromagnet to provide enough electricity to maintain operations for all your car’s electrical needs while the engine is running. It also generates enough power to deliver some back to the battery, topping up its charge. The alternator’s magnetic rotor and copper windings create an alternating current (AC), then a set of diodes in the rectifier convert it to direct current (DC), the type of electricity your car’s devices need in order to operate. The voltage output is regulated to prevent damage from overcharging as well as issues with too little power.  

If the alternator isn’t producing between 13.5 and 14.5 volts, creating noises, or if the wrong type of current is finding its way through the alternator is failing, and it needs to be replaced.  

Signs You May Need a New Alternator 

Repair costs are often unavoidable. Once symptoms of a bad alternator are present, it becomes a question of whether you can avoid extra costs from related repairs. If you have one or more of these symptoms, it might be time to change the alternator. 

  • Dead Battery: The battery sends a massive electrical current to the starter when you crank the engine over. If you have a dead battery, it can be a warning sign that the alternator isn’t replenishing the power drawn by the starter. 
  • Illuminated Battery Light: but it warns of a charging problem. It could be undercharging or undercharging, two conditions that can be caused by a fault alternator, among other things. 
  • Burning Smells: A pungent burning rubber smell may be a belt slipping along the alternator pulley if it’s beginning to seize, and a burning electrical smell could be a fault inside the alternator. 
  • Lighting Issues: You might notice your interior and exterior lights are dimmer than normal or are abnormally bright. There could be flickering as well. This can be from inconsistent voltage from the alternator. 
  • Unusual Electrical Issues: Odd happenings in your car may not seem related to the alternator, but it’s always a possibility. Low voltage can cause slow power window motors, crackling or fading out from the radio, low fan speed, and a host of other electrical problems. 
  • Availability of cores to rebuild. Alternators are either remanufactured or new, and the majority of the aftermarket is remanufactured. Rarer vehicles and options produce rarer alternators, which means there’s less cores coming back to rebuild, which means higher costs. 
  • Whirring Under the Hood: All else might be working fine, but a whirring or whining noise under the hood can spell disaster for the alternator soon. Worn or corroded alternator bearings can mean a seize-up is impending.  

Can I Drive With An Alternator Problem? 

Most of the time, a short drive is fine when the alternator isn’t charging enough. The battery’s reserve power can substitute electricity, such as if you’re driving a few blocks to the repair shop. However, if your alternator is overcharging, it could damage computer modules, the battery, and other electronics or wiring even during a short drive.  

When you detect an alternator problem, it should be a top priority to have it fixed. If you’re unsure if it’s safe to drive, play it safe and arrange a tow truck to get it to your destination.  

How Often Does an Alternator Need to Be Replaced? 

Unlike your brake pads, tires, or even the serpentine belt, it’s tough to gauge how long an alternator will last. For some cars, it will last for the car’s lifetime while for others, it will require replacement more than once during its course of action.  

Generally speaking, an alternator should last in the range of 7 and 10 years. That may be between 100,000 and 150,000 miles. If you’re questioning whether your alternator is functioning properly or you’d like to arrange to test it, an AutoZoner is an excellent resource to tap into with our free Alternator test service.. And if you want to purchase a replacement alternator backed by warranty or get advice on the job, AutoZone can help – or if the job looks to be too big, check out our list of Preferred Shops in your area to help you get back on the road.  Also, if at any time the job appears to be too big, look at our list of local Preferred Shops in your area that can help you tackle the job. 

Advice, how-to guides, and car care information featured on AutoZone.com and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

FREE Loan-A-Tool® program requires returnable deposit. Please note that the tool that you receive after placing an online order may be in a used but operable condition due to the nature of the Loan-A-Tool® program.

Related Posts