If your car’s electrical system is malfunctioning or has a battery warning light on, your alternator might be the sneaky culprit under the hood.
Wondering how long it’ll take to replace an alternator?
Don’t worry; replacing an alternator is usually quicker than you might think, often taking 1 to 2 hours.
In this article, we’ll walk you through the replacement process and explain the factors that can impact the time. This will help you better understand what to expect and plan for your repairs.
This Article Contains:
- How Long Does It Take to Replace an Alternator?
- Replacing an Alternator: A Mechanic’s Step-by-Step Approach
- How Much Does it Cost to Change an Alternator?
- 3 FAQs Related to Replacing an Alternator
How Long Does It Take to Replace an Alternator?
Typically, replacing an alternator takes about 1 to 2 hours, with experienced mechanics often completing the job in as little as 30 minutes.
However, it may require more time if the alternator is located in a hard-to-reach area or if the vehicle has complex systems. For example, some cars have alternators mounted in easy-to-reach spots like the top of the engine bay. Meanwhile, other cars may require removing panels or parts, like the air intake manifold, which can add extra time.
If you decide to tackle the alternator repair yourself, you can expect the process to take approximately 3 to 4 hours, depending on your mechanical experience.
To avoid the hassle and ensure it’s done right, it’s best to let a mechanic handle the job.
Curious about how the replacement is done?
Let’s find out.
Replacing an Alternator: A Mechanic’s Step-by-Step Approach
While you can replace a failing alternator yourself, a professional mechanic has the expertise and tools to ensure proper installation. They can also diagnose any related alternator problem and typically offer a warranty for peace of mind.
Here’s how an auto repair mechanic will replace your old alternator:
NOTE: These replacement steps apply to cars with a serpentine belt. Some older models may have a separate alternator belt, which might need a slightly different process.
- Save the memory: Some mechanics may use a memory-saver device to keep the vehicle’s electronics, such as radio stations and clock settings, intact after disconnecting the car’s battery.
- Disconnect the negative battery cable: They’ll disconnect the battery’s negative terminal to prevent electrical shocks or shorts during the replacement.
- Loosen the belt tensioner: Using a wrench or tensioner tool, they’ll release the tension on the serpentine belt, making it easier to remove from the alternator pulley.
- Remove the serpentine belt: The mechanic will remove the belt from the alternator and other pulleys as needed. They’ll also inspect the belt for any signs of wear and replace it if it’s frayed or damaged.
- Disconnect the wires and wiring harness: They’ll unplug the electrical connectors from the alternator, including the positive cable and any wiring harnesses.
- Loosen and remove the alternator bolts: The mechanic will remove the bolts securing the failing alternator to the engine. They’ll also take note of the bolt positions for reassembly.
- Remove the alternator: They’ll then lift the alternator out of its position, being mindful not to damage any surrounding electrical component, such as the wiring harness.
- Examine the replacement alternator: Before installing the new alternator, they’ll compare it to the old one to ensure it matches in size, connections, and alignment.
- Install the new alternator: They’ll position the new alternator in the engine bay and secure it with the previously removed bolts, ensuring it aligns with other components.
- Reconnect the wiring harness and connectors: They’ll attach the wiring harness and electrical connections to the new alternator.
- Adjust the belt tension: The mechanic will put the serpentine belt back on and tighten it using the tensioner, ensuring it’s properly aligned. Then, reattach the negative battery cable and secure it tightly.
- Test the new alternator: Finally, they’ll start the vehicle to confirm that there’s no alternator issue and all electronics are working. They’ll use a multimeter to test the battery voltage output. If the reading is between 13.5 and 14.5 volts, it indicates a functional alternator.
Now that you know the process, find out how much an alternator replacement can cost you.
How Much Does it Cost to Change an Alternator?
The cost to replace a car alternator varies significantly between vehicle types.
For compact cars, expect to pay between $200 and $300 for a new alternator, with total costs, including labor, ranging from $350 to $600. Luxury vehicles generally have higher costs, with new alternator prices ranging from $500 to $1,300, bringing total replacement costs up to $700 to $1,500.
The final bill may also include costs for additional services, such as an oil change or a voltage regulator check.
NOTE: Though a remanufactured alternator or rebuilt alternator is more affordable, it may not meet the same quality standards as a brand-new one.
Got a few more questions?
We’ve got you covered.
3 FAQs Related to Replacing an Alternator
Here are the answers to three burning questions related to alternator replacement:
1. How Can You Tell If Your Alternator Needs to Be Replaced?
From a dead battery to malfunctioning accessories, here are some symptoms of a bad alternator:
- The battery warning light or the battery light is often the first sign of alternator trouble, indicating a problem with the charging system. Additionally, multiple dashboard lights, like the check engine light, may also pop up due to voltage issues.
- A faulty alternator won’t charge your car’s battery, leading to quick depletion. Even if you have a good battery, under or overcharging will lead to deterioration (bad battery) over time.
- Growling or whining noises often indicate a misaligned alternator belt or worn alternator bearings.
- Overheated alternator components or frayed wiring can emit a rubber or burning smell.
- Due to fluctuating voltage from a defective alternator, your headlights and interior lights may flicker, dim, or become excessively bright.
- A failing alternator can cause slow cranking when starting the engine, as the starter motor may not receive enough power.
- A bad alternator may cause the air conditioning system to not work properly or lose its cooling efficiency.
- If your car alternator isn’t supplying enough power, windows, seat warmers, or other electronics may slow down or stop working.
- Alternator failure can prevent the engine from starting or cause the car to stall frequently.
2. Can You Drive with a Bad Alternator?
No, driving with a faulty alternator is dangerous.
The alternator converts mechanical energy into electrical energy, recharging the car battery and powering your vehicle’s electrical system.
While a good battery may allow you to drive a short distance, a defective alternator can quickly drain a fully charged car battery, leaving you stranded. Over time, you might also have a bad battery as it overworks to compensate for a faulty alternator.
Additionally, in modern cars with electrically assisted power steering, an alternator issue makes steering much harder, increasing the risk of losing steering control.
3. How Long Will a New Alternator Last?
A new alternator typically lasts 7 to 10 years or around 100,000 to 150,000 miles if you follow good driving habits and maintenance schedules.
How often you need a replacement depends on the strain your car’s electrical system endures — regular use of high-powered accessories can wear out the alternator faster.
NOTE: It might be worth consulting a professional to see if upgrading to a higher-amp alternator is a better option for your car.
Count on AutoNation Mobile Service for Your Next Alternator Replacement
A failing alternator can lead to serious electrical issues, like a dead battery or dimming headlights. But taking action now can help you avoid a more costly repair later.
That’s where AutoNation Mobile Service comes in.
We’re a mobile auto repair solution that offers easy online bookings and upfront pricing. We also provide a 12-month | 12,000-mile warranty on all services, like an oil change, alternator repair, diagnosing a check engine light, or replacing worn brake pads.
Contact us to schedule your alternator replacement today!