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3UZ NEW HARNESS PACKAGE

To help you order with confidence, we’ve created a set of short unboxing videos—each one shows exactly what you will receive when you purchase a 3UZ Lexus V8 Custom Standalone Harness.

In these clips you’ll see:

Complete Standalone Engine Harness – brand-new, professionally loomed and clearly labeled.
Optional Pre-Flashed ECU – shown in some videos; this is an optional extra billed separately.
All the small details—connectors, labeling and finish—so you can inspect the quality before you buy.

These videos are a quick way to understand what arrives in the box, whether you’re ordering the harness alone or the complete system with ECU.
👉 Browse the videos above to see the exact components you’ll receive, for either 5-speed or 6-speed manual applications, left- or right-hand drive, with the ECU designed to be cab mounted (glove box area).

3UZ Harness Installation

To help you complete your build with confidence, we’ve created a detailed engine-installation video—showing exactly how to fit the 3UZ Lexus V8 Custom Standalone Harness onto the engine itself.

In this video you’ll see:

Plug-and-Play Engine Connection – how to route and secure the harness cleanly around the 3UZ VVT-i engine and connect every sensor, injector and coil.
Cab-Mounted ECU Placement – recommended location in the glove box (or similar protected cabin area) for easy access and long-term protection.
Professional Securing Tips – how to clip, tie and protect the loom for a factory-quality finish.

Note: This guide covers the engine-side installation only. Final connections to the vehicle—ignition feed, fuel-pump trigger, starter signal and instrument-cluster outputs—are completed by the installer using the supplied pigtail.

👉 Watch the video above to see how simple it is to install the harness on either 5-speed or 6-speed manual applications, for left- or right-hand-drive vehicles, and prepare your 3UZ engine for a clean, reliable start-up.

3UZ Harness Test Run & Diagnostics

To give you complete peace of mind, we finish every build with a full test run and diagnostic scan of the 3UZ Lexus V8 Custom Standalone Harness before it leaves our workshop.

During this final check you’ll see:

Clean First Start – the harness powers the 3UZ VVT-i engine from cold, proving true plug-and-play engine operation.
Complete OBD-II Diagnostic Scan – live verification of all sensor readings and confirmation that no fault codes are present.
System Verification – every key circuit—fuel, ignition and ECU communication—is tested to ensure the harness performs exactly as designed.

Note: This demonstration focuses on the harness itself. Final vehicle-side connections (ignition feed, fuel-pump trigger, starter signal and instrument-cluster outputs) remain the installer’s responsibility and are completed via the supplied pigtail.

👉 Watch the video above to see the 3UZ harness deliver a flawless first start and pass a comprehensive diagnostic scan, whether for 5-speed or 6-speed manual applications, in left- or right-hand-drive vehicles.

3UZ New Custom Harnesses

3UZ Custom Standalone Harness – Plug-and-Play Engine Management

Our brand-new 3UZ Lexus V8 standalone harness is built from the ground up for ultimate reliability and a clean, professional installation. Designed specifically for the 3UZ VVT-i engine, this harness takes the complexity out of wiring your swap while giving you the flexibility to integrate it into virtually any vehicle.

True Standalone, Simple Integration

This is a full standalone engine harness: it provides everything needed for the 3UZ to run exactly as it should.
It is plug-and-play for engine operation, but—just like fitting an aftermarket car radio—it does require a few connections to the host vehicle (power, ground, ignition feed and similar basics). Clear instructions and labeled leads make these final connections fast and straightforward.

Tailored to Your Build

✅ Manual Transmission Ready – Available pre-configured for either 5-speed or 6-speed OEM 3UZ engine managements for manual applications.
✅ Left- or Right-Hand Drive – Harnesses built to suit both LHD and RHD vehicles.
✅ Cab-Mounted ECU Location – ECU is designed to be mounted in the glove box (or similar protected cabin area) for easy access and long-term protection.
✅ OEM-Grade Quality – High-temperature automotive-grade wire, brand-new connectors, and professional loom wrapping ensure years of dependable performance.
✅ Clearly Labeled & Documented – Every connector and sensor lead is explained for a quick, trouble-free install.

Optional ECU Package

Order the harness on its own or choose the optional pre-flashed ECU—complete with immobilizer removal and custom tuning—billed separately.

Why Lexus V8 Engines LLC

Unlike out re-worked factory looms, our new harnesses are 100% new construction, engineered by specialists who focus solely on Lexus/Toyota V8 platforms. You get a professional, swap-ready solution that lets you spend more time driving and less time chasing wiring issues.

Get Started Today

Transform your 3UZ swap into a plug-and-play experience.
👉 Contact us to order your 3UZ Custom Standalone Harness—with or without the optional ECU—tailored for your build.