98-05 3800 Series II simplified harness bundle

1998–2005 GM 3800 Series II Simplified Standalone Wiring Harness (ECM Included)

Our Simplified Standalone Harness for 1998–2005 GM 3800 Series II engines is designed to make your engine swap or race build as simple and reliable as possible. Built using all brand-new wiring and connectors, this harness eliminates unnecessary factory wiring while providing a clean and dependable setup.

Installation is extremely straightforward, requiring only a basic 2-wire hookup to get your engine running.

A tuned ECM is included, giving you a complete plug-and-play solution for your build.

Features

• Designed for 1998–2005 GM 3800 Series II engines

• Simplified standalone wiring system

• Tuned ECM included

• Built with all new wiring and connectors

• Requires only 2 basic connections to run

• Clean layout for easy installation and troubleshooting

• Ideal for race cars, engine swaps, off-road vehicles, and demolition derby builds

Injector Options

Please select the injector style needed for your setup:

• EV1

• Multec

Adapters are also available to convert EV1 to Multec or Multec to EV1 if needed.

Compatibility

These harnesses can also work with older 3800 engines when paired with a 1998–2005 ECM.

Adapters are available for different sensor plugs found on earlier 3800 engines, allowing for smooth compatibility across multiple engine versions.

Important Notes

• Off-road use only

• Not intended for emissions-controlled or street-driven vehicles