LSMainXFIHrnss

FAST offers several main harness options to aC-Commodate most customers' needs. The XFI Main Harness is responsible for connecting your XFI ECU to sensors as well as digital dashes, EGT modules, and various optional accessories. The Main Harness also handles communication between the ECU and ignition devices. Main harnesses are available in TPI, LT-1, LS-1 through 9 (including truck/suv designs), Modern Hemi, Carburetor Conversions and even Rear-Engine Dragsters and Boats. FAST also offers Main Harnesses that come terminated on the sensor side but non-terminated on the ECU side to allow for a truely custom fit. All terminals, seals and connectors are available individually, so don't hesitate to try your hand at crafting your own custom harness from start to finish.

Additional Information

This XFI Main Harness is designed to connect engines that feature GM LS style sensors to our XFI ECU.

Part Type

Fuel Management Wiring Harness

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Product Downloads

#	Document Type	Download
1.	Catalog

Installation guides, warranty details, and other supporting documents are provided by the supplier. In some cases, these files may originate from regions outside your locale, meaning instructions, warranty procedures, and images may not fully align with your specific vehicle or region (e.g., LHD vs. RHD differences, return policies, etc.). If you need clarification, please contact a StreetFX support agent.

Reference Information

Wiring Harness, Fast XFI, ECU, Chevy, Small Block, LS, Kit

FAST XFI main wiring harnesses will allow you to connect the XFI ECU to the main engine wiring harness of your vehicle. They feature pre-terminated ends with special Weatherpack connectors for a perfect fit. Available for different engine configurations and styles, the FAST XFI main wiring harnesses will make the installation of your XFI ECU a lot easier.