What is the purpose of the main harness?

The main harness connects your XFI ECU to sensors, digital dashes, EGT modules, and various optional accessories. It also handles communication between the ECU and ignition devices, ensuring all components work together.

Can I create a custom harness with FAST components?

Yes, FAST offers main harnesses terminated on the sensor side but non-terminated on the ECU side to allow for a custom fit. All terminals, seals, and connectors are available individually, so you can craft your own custom harness from start to finish.

What engine types is this harness compatible with?

This specific FAST Main Wiring Harness (301108) is designed for LS1 and LS2 engines. FAST offers other main harnesses for TPI, LT-1, LS-1 through 9, Modern Hemi, Carburetor Conversions, and even Rear-Engine Dragsters and Boats.

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FAST

FAST Wiring Harness Main LS1LS2L

Name: FAST Wiring Harness Main LS1LS2L
Brand: FAST
Price: 499.96 USD
Availability: InStock

$499.96

Connect your XFI ECU to sensors and accessories. For LS1/LS2 engines.

Key Features

Connects XFI ECU — allows communication with sensors and accessories
Handles ECU to ignition communication — ensures proper engine control
For LS1/LS2 engines — direct fit for these popular engine platforms

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

Will this fit your vehicle?

Compatible with 146 vehicles

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Product Details

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.