558-404 HOLLEY Harness

Review HOLLEY Auxiliary Harness

The Holley 558-404 Fuel System Electric Fuel Pump Wiring Harness is an essential component for any automotive enthusiast looking to upgrade their fuel system with an electric fuel pump. This high-quality wiring harness is meticulously designed to provide a reliable and efficient power connection to your electric fuel pump.

The Holley 558-404 harness is engineered to be a direct replacement for most late model GM applications, making it an ideal choice for those working on their Chevrolet or GMC vehicles. The harness is constructed with top-tier materials, including heavy-duty 12AWG wire, to ensure durability and longevity. The wiring is also insulated with high-temp, Teflon-coated sleeving for added protection against harsh engine bay conditions.

The harness features a convenient inline fuel pump fuse holder, which secures a 15A ATO fuse, ensuring proper fuel pump protection. Additionally, the harness includes a fuel level sending unit connector for easy integration of a sending unit, allowing you to monitor your fuel level.

To ensure a perfect fit and easy installation, the Holley 558-404 harness comes with several pre-terminated connectors, including a crank signal connector, battery and ignition switches, and a fuel pump relay connector. These connectors are color-coded for easy identification and are designed to plug directly into various GM applications, minimizing the need for extensive wiring modifications.

In summary, the Holley 558-404 Fuel System Electric Fuel Pump Wiring Harness is an excellent investment for anyone looking to upgrade their electric fuel pump system. With its durable construction, convenient features, and straightforward installation, this harness is an essential addition to any GM-based project vehicle.

The Holley 558-404 harness is a popular choice among car enthusiasts for their electrical wiring needs in performance applications. This harness is designed to provide a reliable and easy-to-install solution for distributing power and signals to various components in a hot rod or custom-built vehicle. Here are some potential pros and cons to consider before purchasing:

1. Designed for hot rod and custom applications: The Holley 558-404 harness is specifically engineered for the unique electrical requirements of hot rods and custom-built vehicles. It includes a variety of connectors and terminals that cater to different types of ignition systems, fuel pumps, water pumps, and other common accessories.

2. Pre-terminated wires: The harness comes with pre-terminated wires, which saves time and effort during installation. Each connector is labeled and color-coded for easy identification and connection to the appropriate component.

3. Improved reliability: The use of high-quality wires and connectors in the harness can help improve the overall reliability of the electrical system in your vehicle. This can be especially important in performance applications where electrical issues could lead to a loss of power or even engine damage.

4. Easy installation: The pre-terminated wires and clear labeling make installation of the Holley 558-404 harness a relatively straightforward process. This can save time and reduce the frustration often associated with wiring projects.

1. May not fit all vehicles: The Holley 558-404 harness is designed for hot rod and custom applications, which means it may not fit all vehicles out of the box. Be sure to check the compatibility of the harness with your specific make and model before purchasing.

2. Limited customization: While the harness offers a wide range of connectors and terminals, it may not include every possible option for your specific application. This could require additional modifications or customization during installation.

3. Cost: Compared to some other harness options on the market, the Holley 558-404 harness may be more expensive. However, the increased reliability and ease of installation may be worth the additional cost for some users.

In conclusion, the Holley 558-404 harness offers several advantages for those building or customizing a hot rod or high-performance vehicle. Its pre-terminated wires, clear labeling, and compatibility with various components make it a convenient and reliable choice for many applications. However, it may not fit all vehicles and could be more expensive than some other options. Ultimately, the decision to purchase the Holley 558-404 harness should be based on the unique needs and requirements of your vehicle and your budget.

If you are building or customizing a hot rod or high-performance vehicle, the Holley 558-404 harness is a great option to consider for your electrical wiring needs. Its pre-terminated wires, clear labeling, and compatibility with various components make it a convenient and reliable choice for many applications. However, be sure to check its compatibility with your vehicle before purchasing and consider the additional cost compared to other options.

Details:

Quantity: kit. Made from premium materials to ensure superior quality and durability. Manufactured to be tough as nails withstand high-heat and high-pressure conditions.: j4 ecu connector 26 user programmable inputs and outputs.

Holley 558-404 - auxiliary harness. Holley being an undeniable leader in fuel systems for over 100 years, offers a wide range of performance carburetors, pumps, intake manifolds and engine dress up products street performance, race, marine applications. J4 ecu connector, 26 user programmable inputs and outputs menu. Designed to help you maximize your vehicles fuel system efficiency.

Style: sequential multi-port, speed density map-n and speed throttle alpha-n..

specifications ignitioncomp:

• brand: Holley
• mpn: 558-404
• part type: Harness
• country/region of manufacture: Us
• upc: 090127666456

returns ignitioncomp:

• paid by: seller
• policy: returns accepted
• time: 30 days

offer ignitioncomp:

• in stock #: 5
• options: ship-to-home
• availability: in stock
• sold #: 18
• started: june 3, 2025
• prices: $229.95–$259.99
• item condition: New

payments ignitioncomp:

• credit card: diners-club
• other
• wallet: paypal

seller ignitioncomp:

• rating: 97.6%
• city: saint paul, minnesota
• # reviews: 45010

general ignitioncomp:

• category: Auto Parts > Car Truck Accessories > Ignition Systems Components

shipping ignitioncomp:

• type: fixed
• transit: 3-5 days
• class: standard
• service: standard