Metra 70-8117 Factory Amplifier Bypass Harness - Fast Radio Install

In this review of the Metra 70-8117 Factory Amplifier Bypass Harness, the bottom line is simple: this harness is for installers and DIYers who want a faster, non-destructive way to install an aftermarket radio in compatible 2003-2009 Toyota vehicles. The harness plugs directly into the vehicle's original radio connectors and the factory amplifier, supplying electrical power to the new radio without cutting the factory plugs. Its clearest advantage is speed and convenience during installation, though buyers should confirm vehicle fit in the METRA ELECTRONICS VEHICLE FIT GUIDE before ordering.

Key Features

• Direct fit: The harness plugs into the car's original radio connectors and the factory amplifier so installers do not have to cut factory plugs for a quicker install.
• Color-coded wiring: The harness includes color-coded wires on the aftermarket side to make matching and soldering connections to a new radio easier and clearer.
• Includes power harness: The package provides the 70-8113 wiring harness for power so the aftermarket radio receives required electrical connections.
• Long leads: At 204 in total length, the wires give plenty of reach for routing to the dash and behind the new receiver without strain.
• Tech support: Seven-day-a-week tech support is available to help with fitment and installation questions when needed.
• Factory subwoofer note: On select vehicles the factory subwoofer is not retained, so buyers should check audio retention requirements.

Who It's For

The Metra 70-8117 is best for vehicle owners and professional installers working on select 2003-2009 Toyota models who want to replace the factory radio quickly while avoiding cutting vehicle harnesses. It appeals to people who value retaining factory connectors and who have basic soldering or crimping skills to attach the color-coded leads to an aftermarket receiver.

It is not ideal for buyers who need guaranteed retention of factory subwoofers or advanced vehicle interface features such as steering wheel control, navigation integration, or retained video without also purchasing the appropriate interface adapters and dash kits. Confirm fitment in the METRA ELECTRONICS VEHICLE FIT GUIDE before purchase.

Pros & Cons

Pros

• Speeds installation by using vehicle-specific connectors and avoiding cutting factory radio plugs.
• Color-coded wires and included 70-8113 power harness simplify wiring to an aftermarket radio.
• Long wire length gives flexible routing options for installers.
• Accessible tech support is available seven days a week for installation help.

Cons

• Some buyers report mixed fit and sound quality outcomes, so compatibility and results can vary by vehicle and system.
• Factory subwoofer may not be retained on select vehicles, requiring extra parts to keep original audio features.

Specifications

Product type	Factory amplifier bypass wiring harness
Vehicle fit	Select 2003-2009 Toyota models (see METRA fit guide)
Includes	70-8117 harness and 70-8113 power harness
Harness length	204 in
Connections	Plugs to original radio connectors and factory amplifier, color-coded aftermarket leads
Audio retention	Factory subwoofer not retained in select vehicles

Our Verdict

The Metra 70-8117 is a practical, value-oriented option for installers replacing radios in compatible Toyota models who want to preserve factory connectors and speed installation. It provides useful wiring length, color-coded leads, and included power harness, but buyers should confirm fit and accept that retaining certain factory audio features may require additional adapters. For straightforward installs where speed and non-destructive connections matter, it is a sensible buy.

Frequently Asked Questions

Will this harness retain the factory subwoofer?
On select vehicles the factory subwoofer is not retained; check the METRA ELECTRONICS VEHICLE FIT GUIDE for your vehicle and plan to add an adapter if subwoofer retention is required.

Do I need to cut factory wires?
No, this harness plugs into the vehicle's original radio connectors so no cutting of factory radio plugs is needed on the vehicle side.

Is technical help available during installation?
Yes, Metra provides a tech support number available seven days a week to assist with fitment and installation questions.