OEM High-Output Alternator for 2017-2024 BMW

What to Look For When Buying

• Compatibility: Ensure the alternator is designed for your vehicle's year, make, and model.
• Amperage Output: Verify the alternator's amperage output matches or exceeds the original equipment specifications.
• Warranty: Check for a warranty that covers defects in materials and workmanship.

Quality Indicators

• Reputable Brand: Choose alternators from well-known and trusted manufacturers.
• Quality Components: Look for alternators with high-quality internal components, such as bearings and regulators.
• Testing and Inspection: Ensure the alternator has been thoroughly tested and inspected to meet performance standards.

What's Typically Included

• The alternator itself
• Mounting hardware (sometimes)
• Installation instructions (sometimes)

Difficulty Level and Estimated Time

Replacing an alternator is generally considered a moderate DIY project. Estimated time: 2-4 hours.

Special Tools Needed

• Socket set
• Wrench set
• Multimeter
• Belt tensioner tool (may be required)

Critical Steps and Tips

1. Disconnect the Battery: Always disconnect the negative battery cable before starting any electrical work.
2. Locate the Alternator: Identify the alternator and its mounting bolts.
3. Remove the Belt: Use a belt tensioner tool to release tension on the serpentine belt and remove it from the alternator pulley.
4. Disconnect Wiring: Disconnect the electrical connectors from the alternator.
5. Remove the Alternator: Unbolt the alternator from its mounting bracket and carefully remove it.
6. Install the New Alternator: Install the new alternator in the reverse order of removal.
7. Reconnect the Battery: Reconnect the negative battery cable.

DIY or Professional Installation?

While replacing an alternator can be a DIY project, professional installation is recommended if you are not comfortable working with electrical systems or if you lack the necessary tools. A professional can ensure the alternator is properly installed and that the electrical system is functioning correctly.

Here's a comparison of the available options:

Used OEM

Used OEM alternators offer the best value. These are genuine factory parts that have been tested and inspected to ensure they are in good working condition. They are available at significantly lower prices than new alternators.

Refurbished OEM

Refurbished OEM alternators are factory parts that have been professionally restored with new components. This option provides a balance of price and reliability.

New Aftermarket

New aftermarket alternators are brand new third-party parts built to OE specifications. These can be a good option if you prefer a new part and are willing to pay a bit more.

• Serpentine Belt: The belt that drives the alternator. A worn or cracked belt can cause the alternator to malfunction.
• Battery: A weak or failing battery can put extra strain on the alternator.
• Battery Terminals: Corroded or loose battery terminals can interfere with the alternator's charging ability.
• Voltage Regulator: The voltage regulator controls the alternator's output voltage. A faulty regulator can cause overcharging or undercharging.

Replacing these parts at the same time can prevent repeat failures and ensure the electrical system is functioning optimally.

A high-output alternator typically lasts between 5 to 10 years or 80,000 to 150,000 miles.

Factors that affect longevity:

• Driving conditions (frequent short trips can shorten lifespan)
• Climate (extreme temperatures can affect performance)
• Electrical load (high electrical demands can strain the alternator)
• Maintenance (regular inspections can identify potential problems early)

• Used OEM: $75 - $150
• Refurbished OEM: $150 - $250
• New Aftermarket: $200 - $400

Labor costs for installation typically range from $100 to $300, depending on the mechanic's hourly rate and the complexity of the job.

Total job cost estimates:

• Used OEM: $175 - $450
• Refurbished OEM: $250 - $550
• New Aftermarket: $300 - $700

Some 2017-2024 BMW and Toyota models have known issues with the electrical system, including voltage fluctuations and premature alternator failure. Check for any Technical Service Bulletins (TSBs) related to the alternator or charging system for your specific vehicle model. Some owners have reported issues with the voltage regulator causing overcharging.

After installing the new alternator, verify proper operation by:

• Checking the Battery Voltage: Use a multimeter to check the battery voltage with the engine running. It should be between 13.5 and 14.5 volts.
• Listening for Unusual Noises: Listen for any unusual noises, such as whining or grinding, coming from the alternator.
• Observing the Battery Warning Light: Ensure the battery warning light on the dashboard is off.
• Testing Electrical Components: Test various electrical components, such as headlights, power windows, and radio, to ensure they are functioning correctly.

FAQ

Q: How do I know if my alternator is bad or if it's just my battery?
A: A simple test is to jump-start your car. If it starts and runs fine, but dies shortly after removing the jumper cables, it's likely the alternator. If it doesn't start at all, it could be the battery. Have both tested to be sure.

Q: Can I drive with a bad alternator?
A: It's not recommended. A bad alternator can cause your car to stall, leaving you stranded. It can also damage other electrical components.

Q: Will a new high-output alternator fix my dimming headlight problem?
A: If the dimming headlights are caused by a weak alternator, then yes, a new high-output alternator should fix the problem. However, dimming headlights can also be caused by other issues, such as poor wiring or a weak battery.

Q: What does "OEM" mean?
A: OEM stands for Original Equipment Manufacturer. It means the part was originally made by the same manufacturer that made the parts for your car when it was new.

Q: How long does it take to install a new alternator?
A: On average, it takes about 2-4 hours to install a new alternator. The time can vary depending on the vehicle model and the mechanic's experience.

OEM Part Numbers:

• BMW: 12318634166, 12318634167, 12318654280, 12318689830, 12318689831, 12318689832

Fits Years: 2017 2018 2019 2020 2021 2022 2023 2024