What is an alternator?
All cars that run on petrol or diesel (other than some hybrid models) will have an alternator. The alternator is basically a generator that uses the energy from your car engine to help power the electrical parts of your car and to recharge your car battery.
It’s easy to assume that your battery powers most of your car’s electrical elements, like your interior and exterior lights, your dashboard and your windscreen wipers. But this isn’t strictly true. Instead, your battery mostly provides power to start your car, while your alternator feeds the electrical system the rest of the time.
Alternator repair average costs
The average cost of an alternator repair is £340.44, booked on WhoCanFixMyCar. That said, the cost of repairing an alternator can vary quite a lot depending on a variety of factors. One of the biggest will be the make and model of your car. You can get a rough idea of alternator repair costs for a range of car makes below.
|Car Make||Average Price|
Which alternator repair service do I need?
If your car isn’t performing as it should be and you suspect there’s a problem with the alternator, a mechanic will be able to help. There’s a range of different services they can provide you with depending on the symptoms you’re experiencing and the issues they uncover with your alternator.
The average cost of an alternator repair when booked on WhoCanFixMyCar is £335.80. An alternator is a fundamental part of your car's electrical system and allows components such as your lights, dashboard, windscreen wipers, and radio to function. If you're experiencing a problem with your car's electronics, you may need an alternator repair.Can include
- Testing and diagnosis
- Alternator repair
- Alternator replacement
The average cost of a car diagnostic booked on WhoCanFixMyCar is £48.
Car diagnostics testing involves plugging your vehicle into special software that can reveal issues with its engine, electrical system, transmission, braking, exhaust system, and more. A specialist will run tests on your vehicle to expose the cause of any problems you're having with your car.Can include
- Full diagnostic testing
- Recommended repairs
The average cost of a mobile mechanic booked on WhoCanFixMyCar is £62.54.
A mobile mechanic will visit you at your home or workplace and can carry out a wide range of different repairs. If the repair is more complex, the mechanic will collect your car, take it to a garage to be repaired, and drop it off when it's finished. The exact cost of a mobile mechanic will depend on the repair you need.Can include
- Home visit
- Tyre change
- Oil change
- Recommended repairs
Common alternator problems
You’ll usually experience a problem with the alternator at some point in your car’s lifetime, as issues of this kind are pretty common.
One problem that often crops up is to do with a part of the alternator called the rotor. The rotor has magnetic poles attached to it and is responsible for creating magnetic flux by spinning. Issues with bad bearings can cause the rotor to seize up, while a bad belt can prevent it from spinning as it should so the alternator doesn’t get the power it needs.
Another common problem is with the alternator’s copper coils. These turn the magnetic flux that’s generated into alternating current, which later gets turned into direct current (the form of power needed to run the car’s electrical system and get stored in the battery).
Nearly all alternator faults are best solved by replacing the alternator completely, rather than trying to fix it. You may be able to recondition your alternator, which is where you replace individual parts of it, but in general, a new alternator is likely to last longer.
Likewise, if you need a replacement alternator, you may be able to save money by getting a reconditioned alternator fitted rather than forking out on a new one. However, this won’t usually be in as good a condition so we’d recommend making sure that your mechanic fits a new one if you have the budget.
You can find some more of the common signs of alternator problems in our blog here.
Top warning signs your alternator needs attention
Often, the signs of a faulty alternator look similar to the signs of a faulty car battery and vice versa. So, it can be difficult to know exactly what’s going wrong with your car. That said, if you notice any of the following symptoms, it’s important to get your car checked by a professional who’ll be able to inspect it and find out what the fault is.
Your car won’t start. If your car won’t start, this is usually because of a dead battery, which could indicate that your alternator isn’t charging it adequately.
Noises coming from the engine area. If you hear noises like squealing or growling, this might be a sign that the parts of the alternator that spin are having issues.
Dashboard warning lights. If your alternator isn’t providing the power that the electrical system needs, you might get warning lights popping up like the battery light or ‘check engine’ light.
Electrical issues. If you notice that some of the electrical components of your car aren’t working as they should, like your radio, indicators or aircon, the alternator might not be providing enough power.
Smell of burning. In bad cases, electrical issues or rubber parts rubbing together might create a burning smell. If this happens, stop driving straight away and call a professional.
Engine stalling. In newer cars, a bad alternator might cause your engine to stall. This could be because the combustion chamber isn’t getting the right amount of fuel at the right time.
When do I need an alternator replacement?
Most alternators last between 80,000 and 120,000 miles, or between 5 and 8 years. So, the chances are that you’ll need a new alternator somewhere around that mark.
However, there isn’t really a recommended timeframe for alternator replacements. Some alternators can last a lot longer than the average, while some can last a lot less. Having an old battery, a belt that’s too tight or fluids leaking onto the alternator can all contribute to an alternator that fails early.
The best thing you can do is simply to keep an eye out for any of the symptoms we listed above and, if you spot any, go straight to a mechanic. Although you can often still technically drive your car with a faulty alternator (as long as it’s not causing your engine to stall), it usually won’t charge your battery enough so you’ll have to keep replacing or jump-starting your battery. If your faulty alternator results in dashboard warning lights or other important electrical elements to stop working, your car could also be dangerous to drive.
Find out about the car alternator and common signs of failure
What impacts the cost of an alternator repair?
The total cost of getting your faulty alternator repaired will depend on lots of different things. Some of the main ones are:
Whether you use an independent garage or a dealership
The make and model of your car
Whether you need a repair or replacement
Whether you choose a new or a reconditioned alternator (if you’re getting an alternator replacement)
Whether other parts need to be replaced at the same time (it’s often wise to replace the belt when you repair your alternator)
Where can I find garages to fix an alternator near me?
Replacing a faulty alternator is a relatively straightforward job that’s offered by pretty much every garage or mechanic. Usually, it should only take between 1 and 3 hours although it can take a bit longer on vehicles where the alternator is hard to access.
To get your alternator repair or replacement at the best price, it’s always worth comparing a few quotes from different garages. You’ll usually also find that repairs carried out at a dealership are pricier than those carried out at a local, independent garage.
Can a mobile mechanic fix an alternator?
An alternator replacement is a job that can be easily carried out at your home by a mobile mechanic. This is especially useful given that a faulty alternator can often result in a dead battery. Getting a mechanic to come to you rather than dropping your car off at a garage yourself will save you from having to jump-start your car to drive it in.
You might think that you’d pay more for the convenience of getting your car repaired at home, but in reality, mobile mechanics are often cheaper than garages. This is because they won’t have the overheads that come with working at a fixed location and so they can usually charge a bit less.
What is alternator reconditioning?
Alternator reconditioning is when an old, faulty alternator is repaired by replacing any parts of it that aren’t working properly. If you need an alternator replacement, you can buy a reconditioned alternator instead of a new one to save money. However, it’s riskier. So, if you have the budget, it’s usually preferable to buy a new alternator.
How much is an alternator?
The average cost of an alternator replacement is around £340.44 when booked with WhoCanFixMyCar. The cost of buying an alternator varies a lot depending on the make and model of your car. Generally, more expensive cars will have parts that cost more.
Can an alternator be repaired?
Yes, alternators can be repaired. However, it’s nearly always better and more cost-effective to replace a faulty alternator instead of fixing it.
Is it worth replacing an alternator?
Yes! If your alternator isn’t working properly, you’ll need to get the problem solved as soon as possible. Otherwise, you’re going to experience issues like a dead battery. It’s nearly always worth replacing rather than repairing a faulty alternator, as this way, your alternator will usually last longer.
How often should an alternator be replaced?
You should consider replacing your alternator whenever you experience any issues with it. However, most alternators need replacing every 80,000 to 120,000 miles, or every 5 to 8 years.
Does an alternator repair or replacement fall under warranty?
An alternator repair or replacement isn’t considered standard maintenance work, so it’s likely to fall under warranty (as long as the damage wasn’t caused by an accident or something similar). Just make sure to check your warranty carefully as each one is different.
Is an alternator repair or replacement covered by insurance?
That depends on what kind of insurance you have. If you have a comprehensive insurance policy (which covers damage to your car as well as other people’s cars) then your alternator repair or replacement will often be covered. That said, you should check your insurance policy to make sure as no two policies are the same.