2000–2005 GM 3100/3400 Simplified Harness — ECM & Injector Adapter Sold Separately

2000–2005 GM 3100/3400 Simplified Harness

In-stock standalone harness for 2000–2005 GM 3100/3400 builds — ECM and injector adapter sold separately.

This LMMF simplified standalone harness is built for 2000–2005 GM 3100 and 3400 V6 engines. It removes unnecessary factory wiring and gives your demolition derby, race, off-road, or engine-swap build a clean, dependable wiring setup using new wire, new connectors, and quality components.

Kept in stock • Usually ships within 1–2 business days • ECM sold separately • Injector adapter sold separately

Fits

• 2000–2005 GM 3100 / 3400 V6 engines
• 2000–2005 injector configurations
• Demolition derby, race, off-road, and simplified engine-swap builds

What’s Included

• Professionally built simplified standalone 3100/3400 engine harness
• All-new wiring, new connectors, and quality components
• Essential wiring circuits for a clean, simplified installation

What Is Not Included

• Tuned ECM
• Injector adapter

ECM Sold Separately

This listing is for the harness only. A tuned ECM is not included. For a compatible ready-to-run ECM, shop the LMMF 1998–2005 GM 3100/3400 Tuned ECM — No Core Required.

Injector Adapter Sold Separately

This harness is designed for 2000–2005 injector configurations. It does not include an injector adapter.

If you need a setup that works across the 1996–2005 3100/3400 range, choose the LMMF 1996–2005 GM 3100/3400 Harness + Tuned ECM Package. That complete package includes the tuned ECM and injector adapter needed to cover the additional injector configurations.

In Stock & Fast Shipping

These harnesses are kept in stock and usually ship within 1–2 business days.

Before You Order

• Confirm that your engine is a 2000–2005 GM 3100 or 3400 V6.
• Confirm that you have a 2000–2005 injector configuration, or purchase the required injector adapter separately.
• Contact LMMF before ordering if you are unsure about engine year, injector style, ECM requirements, or vehicle compatibility.

Need the complete setup? Choose the 1996–2005 Harness + Tuned ECM Package for the harness, ECM, and injector adapter in one order.

Plug it in. Pair it with the right parts. Send it.