The alternator is integral to your vehicle’s electrical system, providing power to the car’s battery and other systems. A malfunctioning alternator can cause various issues with your car, which can be dangerous and costly.
Have you experienced dimming headlights, a weak or dead battery, strange noises or smells, or difficulty starting your vehicle? In that case, these can all be signs that you may have an issue with your alternator.
Keep reading to discover what factors influence alternator replacements so you can know when it’s time to replace your alternator.
What Is A Car Alternator?
Under the hood, an alternator looks like a small cylindrical generator. You will typically find it bolted to the engine. A car alternator, along with the battery and voltage regulator, is one of three main parts of a vehicle’s electric charging system.
What an alternator does is supply electricity to be stored in a vehicle’s battery. It is the alternator’s function to take in mechanical power from a drive belt or serpentine belt connected to the engine’s crankshaft pulley and then convert this mechanical energy into electricity.
What Are An Alternator’s Key Elements?
The stator and the rotor are considered to be the main elements of a car alternator. The stator is a package of steel plates assembled in several blades along the circumference and wrapped with copper wire; each blade has a strictly defined number of coils.
The rotor consists of a steel lug (shaft) with wedge-shaped projections and notches. This shaped shaft is wound with copper wires and has a certain number of turns on each shaft. It is called excitation winding. Its leads are connected to the contact rings. When the rotor rotates, an electric voltage is generated in the stator.
The standard voltage in the alternator of a modern car is 13.8 to 14.6 volts. It is sufficient for the regular operation of electrical devices, including battery charging. If the voltage is lower, the battery will not be charged.
The onboard network will consume your battery and eventually discharge it. The orange or sometimes even red indication on the instrument panel indicates a lack of power. Stop the vehicle, switch off the engine, and call a service technician.
You can continue driving at your own risk, but in this case, all electrical devices and equipment will be powered by the battery, and in the event of battery failure, you will have to buy a new one.
How Do You Know if a Car Alternator is Bad?
It can be difficult to tell whether your car has a bad alternator or a bad battery. If you jumpstart your car but it dies immediately after, you most likely have a problem with your alternator. Some warning signs of a failing alternator include:
- Trouble starting your car.
- Frequent stalling
- Whining or screeching noise after the vehicle starts.
- Dim or overly bright lights.
- Smell of burning rubber or wires
- Dead battery
- Battery dashboard warning light is on.
Other signs include a whistling drive belt, belt overheating or collapse, ringing or rustling sound from under the hood, or electric hum.
Common Causes of Alternator Failure
As frustrating as it may be to have an alternator malfunction, understanding why it occurred can help prevent the same issue from happening in the future. From a mechanical standpoint, alternators typically fail due to:
- Long-term wear and tear
- Leaking fluid
- Worn-out bearings
- A slipping belt
- Incorrect use of jumper cables
Driving habits can play a role as well but to a lesser degree.
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 considering its specs.
- 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.
How Much Does It Cost To Replace An Alternator?
Alternators can average anywhere from $100 to $350, depending on the model. In most cases, costs will average between $350−400 for the alternator replacement if no other parts need to be changed. Add another $20 to $50 to your bill if the serpentine belt has to be replaced as well.
If you decide to go with dealership parts and labor, expect the bill to climb over $500 in many cases. Because the total cost depends on the vehicle, you can expect to pay anywhere between $350−$900 for an alternator replacement.
We’ve collected estimates for replacing an alternator on nine example vehicles in Austin, Texas to give you examples of what this service might cost.
| Vehicle | Parts cost | Labor cost | Total cost |
| 2016 Honda Civic | $427.01 to $733.92 | $164.27 to $223.24 | $591.28 to $957.16 |
| 2016 Ford F-150 | $447.09 to $768.44 | $82.13 to $111.62 | $529.23 to $880.06 |
| 2018 BMW 740i | $1,227.88 to $2,110.42 | $401.54 to $545.69 | $1,629.42 to $2,656.10 |
| Buick LeSabre | $218 to $489 | $70 to $89 | $288 To $578 |
| Porsche 911 | $419 to $1606 | $123 to $156 | $542 to $1762 |
| Dodge Grand Caravan | $244 to $341 | $123 to $156 | $367 to $497 |
| Dodge Caravan | $182 to $341 | $96 to $123 | $278 to $464 |
| Dodge Dakota | $213 to $390 | $52 to $67 | $265 to $457 |
| Jeep Wrangler | $235 to $425 | $61 to $78 | $296 to $503 |
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.