FAST XFI Main Harness

Fits Most Chrysler/Dodge/Jeep/Ram 5.7L Hemi (03-18)

301104

Overview:

The FAST XFI Main Harness is a critical component designed to seamlessly connect your FAST XFI ECU to a wide range of sensors, digital dashboards, EGT modules, and optional accessories. Engineered specifically for Mopar-style sensor integration, this harness ensures reliable communication between the ECU and ignition devices, providing a robust foundation for your engine management system. Ideal for enthusiasts and professional tuners alike, the XFI Main Harness supports a broad spectrum of Dodge, Chrysler, Jeep, and Ram vehicles from 2003 through 2018, making it a versatile solution for many popular models.

Whether you are upgrading your engine management system or building a custom wiring setup, this harness offers the flexibility and durability needed to maintain precise sensor data and ignition control. Its compatibility with multiple vehicle platforms ensures that you can rely on FAST’s proven technology for your performance or restoration project.

Key Features:

The FAST XFI Main Harness delivers a comprehensive wiring solution with features tailored to meet the demands of modern and classic Mopar engines:

• Direct integration with Mopar-style sensors for accurate data transmission
• Supports communication between the XFI ECU and ignition components
• Compatible with digital dashboards and exhaust gas temperature (EGT) modules
• Available in multiple configurations including TPI, LT-1, LS series, Modern Hemi, and carburetor conversions
• Options for sensor-side terminated or fully customizable ECU-side connections
• All terminals, seals, and connectors sold separately for custom harness fabrication
• Designed to accommodate a wide range of Dodge, Chrysler, Jeep, and Ram models from 2003 to 2018
• Robust construction to withstand harsh automotive environments
• Facilitates easy integration of optional accessories and aftermarket modules

Construction & Design:

Built with high-quality materials and engineered for durability, the FAST XFI Main Harness features premium connectors and sealed terminals to resist moisture, heat, and vibration commonly encountered in engine bays. The harness is designed for straightforward installation while maintaining the flexibility to support custom wiring projects. Its modular design allows users to terminate connections on either the sensor or ECU side, enabling tailored setups that fit specific vehicle and performance requirements.

Each harness undergoes rigorous quality control to ensure reliable signal integrity and long-term performance. The use of OEM-style connectors ensures compatibility with factory sensors and ignition components, reducing installation complexity and enhancing system reliability.

Installation & Fitment:

The FAST XFI Main Harness is engineered for direct fitment on a wide range of Dodge, Chrysler, Jeep, and Ram vehicles from model years 2003 through 2018. Installation is straightforward for experienced technicians and enthusiasts familiar with engine management systems. The harness connects directly to the XFI ECU and factory sensors, minimizing the need for splicing or modifications.

For custom applications, the harness can be ordered with sensor-side termination only, allowing users to craft a fully custom ECU-side connection. This flexibility makes it suitable for both OEM replacement and highly specialized builds. Proper routing and secure mounting are recommended to protect the harness from heat and mechanical damage.

What's Included:

• FAST XFI Main Harness tailored for Mopar sensor integration
• Factory-style connectors and sealed terminals (pre-installed)
• Comprehensive wiring to interface ECU with sensors, ignition, and accessories

Ideal For:

This main harness is perfect for performance enthusiasts, professional tuners, and custom builders working on Dodge, Chrysler, Jeep, and Ram vehicles equipped with Mopar-style sensors. It supports a wide range of applications including street performance, racing, restoration, and engine swaps. Whether upgrading to a FAST XFI ECU or building a custom wiring solution, this harness provides the reliability and flexibility needed for precise engine management.

FAST (Fuel Air Spark Technology) develops aftermarket EFI and engine-management solutions for high-performance street and race builds. From throttle-body and multi-port EFI systems to supporting ignition and fuel-system components, FAST is aimed at enthusiasts who want modern tunability, cleaner drivability, and strong power potential.