Your Guide To Upgrading To A High Output Alternator: Do You Really Need One?

As automotive technology continues to evolve, vehicle owners increasingly seek to enhance their driving experience by adding various accessories and upgrading their car’s audio system. While these additions can undoubtedly improve one’s driving experience, they can also significantly strain the vehicle’s electrical system, particularly the alternator.

Consequently, it is essential to understand the potential benefits and considerations of upgrading to a high-output alternator to ensure that the vehicle’s electrical needs are adequately met without compromising its overall performance.

This comprehensive guide will focus on the advantages of upgrading to a high-output alternator, including the increased power requirements and the impact on the vehicle’s electronics. Furthermore, the article will explore potential modifications necessary for a successful upgrade, such as choosing the right gauge cables and determining the electrical load of standard vehicle accessories.

By examining these critical factors, vehicle owners will be better equipped to decide whether a high-output alternator suits their specific needs, ultimately enabling them to achieve a greater sense of liberation and satisfaction from their driving experience.

Benefits Of A High-Output Alternator

The advantages of utilizing a high-output alternator in a vehicle’s electrical system are numerous, mainly when catering to increased power demands from various components and accessories.

High-output alternators are designed to provide a more excellent amperage supply than their standard counterparts, allowing for a more stable and efficient performance of the vehicle’s electrical system. This increase in amperage capacity enables the electrical system to cope with the demands of additional upgrades, such as robust car audio systems or other aftermarket modifications.

As a result, the benefits of upgrading to a high-output alternator extend to the enhanced performance of the vehicle’s electrical components and the improved reliability and longevity of these systems.

In addition to the direct advantages of increased amperage capacity, a high-output alternator upgrade can positively impact the overall health and efficiency of a vehicle’s electrical system. By providing a more stable and consistent power supply, a high output alternator can help mitigate the risk of voltage drops and system failures, which can be detrimental to the vehicle's performance and its components.

Furthermore, this enhanced stability can also contribute to preserving the vehicle’s battery life, as the increased amperage output reduces the strain placed on the battery when attempting to compensate for power deficits. Ultimately, the benefits of upgrading to a high output alternator are manifold, encompassing the immediate improvements in electrical system performance and the long-term safeguarding of the vehicle’s electrical components.

Understanding Low Voltage Or Low Idle Output: Why Are My Headlights Dimming?

Low voltage or low idle output issues often manifest as dimming headlights, a symptom of a bad alternator struggling to supply sufficient power to the vehicle’s electrical system and audio components.

The electrical load on your vehicle increases with the addition of high-performance audio equipment. If your stock alternator cannot handle the increased demand, it may result in headlight dimming and other electrical issues.

Upgrading to high output alternators can help alleviate these problems by providing the additional power needed to support the added components.

  1. High output alternators are designed to deliver more amperage than standard alternators, allowing them to handle the increased electrical load from aftermarket car audio systems.

  2. Upgrading your alternator can help prevent headlight dimming by ensuring your vehicle has enough power to support the electrical system and the added audio components.

  3. Low voltage issues can also cause problems for other components in your vehicle, so it is essential to address them as soon as possible to avoid further damage.

In conclusion, if you have invested in a high-performance car audio system, it may be necessary to upgrade your alternator to ensure that your vehicle can handle the additional electrical load.

High output alternators can help prevent headlight dimming and other low-voltage issues by providing the necessary power to support the electrical system and the car audio components.

By upgrading your alternator, you can enjoy your powerful car audio system without compromising the performance of your vehicle’s other essential functions.

How To Determine The Right Amperage

Determining the appropriate amperage for your vehicle’s electrical system is crucial to ensure optimal performance and avoid potential issues arising from an inadequate power supply. When upgrading to a high output alternator, it is essential to calculate the combined amperage requirements of your vehicle's electrical components to determine the necessary amperage output. This will help you choose the right higher output alternator to sufficiently power your upgraded system without overloading or damaging any components.

To determine the amperage output you need, consider the wattage of your vehicle's electrical components and use the formula WATTS ÷ VOLTS = AMPS. Here is a table that provides some common electrical components and their approximate wattage:

Component Approximate Wattage
Headlights 100 - 200 W
Air conditioner 500 - 1000 W
Stereo system 200 - 2000 W
Electric fans 100 - 300 W

By calculating the total wattage of your electrical components and dividing it by the average voltage of your vehicle (usually around 13.5 volts), you can determine the amperage output your upgraded alternator should have. Remember that this calculation is only an estimate, and it is always advisable to consult a professional before modifying your vehicle’s electrical system. Feel free to contact the JS Alternator Customer Service Team if you have any questions. 

Electrical Load Of Common Vehicle Accessories

Understanding the electrical load of standard vehicle accessories is vital for determining the suitability of upgrading to a high output alternator, ensuring optimal performance and preventing potential issues. By evaluating the amperage requirements of various accessories, one can make an informed decision about whether or not a high-output alternator is necessary. Factors to consider include the total power consumption of the supplements, the vehicle’s factory alternator capacity, and the possible need for additional wiring upgrades.

When assessing the electrical load of standard vehicle accessories, it is essential to consider the following:

  • Aftermarket audio systems: High-powered amplifiers and subwoofers can significantly increase the demand for amperage, potentially requiring a high output alternator to maintain optimal performance.

  • Auxiliary lighting: Additional LED or HID lights, such as off-road or driving lights, can draw a substantial amount of power, which may necessitate an alternator upgrade.

  • Electric fans and cooling systems: Upgraded cooling systems, including electric fans or water pumps, can strain the electrical system, requiring a higher amperage capacity.

Considering the electrical load of these and other vehicle accessories, one can more accurately determine the necessity of upgrading to a high-output alternator. Doing so will help ensure the vehicle’s electrical system can handle the additional amperage demands, improving performance and reliability.

The Importance of Upgrading to a Big 3 Wiring Kit

The Big 3 Wiring Kit is REQUIRED for ALL High Output Alternators and is crucial in enhancing the efficiency and performance of a vehicle’s electrical system when upgrading to a high output alternator.

This kit is specifically designed to handle the increased current flow of a higher output alternator. It consists of thicker, high-quality cables replacing stock power and ground wires.

By upgrading to a Big 3 Wiring Kit, car owners can ensure that their charging system is optimized for the increased power demands of their upgraded car audio system or other high-draw accessories.

When installing a high-output alternator, taking the necessary precautions and incorporating the Big 3 Wiring Kit into the upgrade process is essential.

This kit ensures the safe and efficient operation of the charging system and helps prevent potential issues related to overloading the factory wires.

Additionally, upgrading to a higher output alternator without the proper wiring can lead to early failure of the alternator itself, as well as other electrical components in the vehicle.

Therefore, investing in a Big 3 Wiring Kit is crucial in achieving optimal performance and reliability from a high output alternator upgrade.


In conclusion, upgrading to a high-output alternator can provide numerous advantages for vehicles with increased power demands due to enhanced audio systems or other power-intensive accessories.

Ensuring the appropriate amperage and upgrading the vehicle’s wiring with a Big 3 Wiring Kit are vital steps in achieving optimal performance and safeguarding the electrical system.

As vehicle owners weigh the benefits and considerations of a high-output alternator, an informed decision can be made that considers power requirements, potential modifications, and the impact on the car’s electronics.

By doing so, individuals can adequately address their vehicle’s specific needs and enhance its performance for years.