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Welcome to our new Site We are adding some final touches. For other T-harnesses Options please visit T-harness.com. Thank you
Welcome to our new Site We are adding some final touches. For other T-harnesses Options please visit T-harness.com. Thank you
LLJ Customs

LLJ Customs

This collection will include all our LLJ Customs signature items like our Elite OEM Loopback Harness, Automotive Amp Racks, Elite T-harness, Pair runner wire guide ruler, etc. When it comes to factory system integration we are number one. Our products are designed with you in mind. We make our products to work with your favorite factory system integration.

GM/GMC Bose amplifier harness Base connector 2014-2019

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
Out of stock

Our Bose amplifier harness is designed to work with a variety of GM/Cadillac vehicles from a Silverado, Escalade, Sierra and any GM vehicle with...

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Bose ANC bypass harness for 2013-2023 GM/GMC/Cadillac

LLJ Customs Car Audio Fabrication
Original price $15.00 USD - Original price $15.00 USD
Original price
$15.00 USD
$15.00 USD - $15.00 USD
Current price $15.00 USD
In stock

Our Bose ANC bypass harness is the first in the world. We developed the Bose ANC bypass harness to disable the Bose ANC microphones in your vehi...

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RAM jeep ANC bypass harness 2018-2023

LLJ Customs Car Audio Fabrication
Original price $15.00 USD - Original price $15.00 USD
Original price
$15.00 USD
$15.00 USD - $15.00 USD
Current price $15.00 USD
Out of stock

The RAM jeep Active Noise Cancellation, or ANC, in your vehicle is designed to pick up on low frequency road noise and cancels out any undesirable...

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2014-2018 GM/GMC vehicles with 8" or select 4" screen's (Without Bose) Base Connector

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our 8" screen GM/GMC harness is designed to work with a variety of vehicles from a Silverado, Sierra, Suburban and any other GM vehicles that use ...

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Elite 2ch T-Harness Accessory

LLJ Customs Car Audio Fabrication
Original price $30.50 USD - Original price $92.00 USD
Original price
$30.50 USD - $92.00 USD
$30.50 USD - $92.00 USD
Current price $30.50 USD
In stock

The Elite 2 Channel T-Harness Accessory is the option needed when installing a mono amp and subs. This will offer signal, power and ground to the L...

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GM/GMC Bose amplifier harness base Connector 2019-2025

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
Out of stock

The Bose amplifier harness is designed to work with a variety of GM/Cadillac/GMC and Buick vehicles from a Silverado, Escalade, Sierra and any G...

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GM/GMC/Cadillac Aqua & Tan (Without Bose amp) Base Connector 2019-2025

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our 2019-2025 GM/GMC/Cadillac Aqua & Tan Elite Harness has been tested, redesigned and modified to what it is now by our team at LLJ Customs....

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GM Bose T-harness 2013-2024 R2R

LLJ Customs Car Audio Fabrication
Original price $240.00 USD - Original price $240.00 USD
Original price
$240.00 USD
$240.00 USD - $240.00 USD
Current price $240.00 USD
Low stock

The GM Bose T-harness design lets you add a subwoofer in minutes. Our plug and play Bose T-harnesses are guaranteed to deliver the signal you need...

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GM/GMC/Cadillac Black & Gray (Without Bose amp) Base Connector 2019-2025

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our 2019-2022 GM/GMC Black & Gary connector Elite Harness has been tested, redesigned and modified to what it is now by our team at LLJ Customs...

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Uconnect4 RAM JEEP Elite harness base connector 2013-2022

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our versatile RAM JEEP Uconnect4 Elite Base Connector is compatible with a range of RAM JEEP vehicles including the RAM pickup, wrangler sport, Ra...

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FORD Sync 3 Elite harness base connector 2011-2020

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our versatile Ford Sync3 Elite Base Connector is compatible with a range of Ford Sync3 vehicles including the F150, Mustang, Explorer, and more ...

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Elite 4ch OEM Loopback Harness Accessory

LLJ Customs Car Audio Fabrication
Original price $205.00 USD - Original price $315.00 USD
Original price
$205.00 USD - $315.00 USD
$205.00 USD - $315.00 USD
Current price $205.00 USD
Out of stock

Introducing our Elite Loopback Harness Accessory: The Seamless Solution for Adding a 4+ Channel Amp to Your Speaker System! Are you looking to upgr...

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GM/GMC ANC bypass harness (Select Vehicles) 2018-2023

LLJ Customs Car Audio Fabrication
Original price $15.00 USD - Original price $15.00 USD
Original price
$15.00 USD
$15.00 USD - $15.00 USD
Current price $15.00 USD
In stock

Our GM/GMC ANC bypass harness works for vehicles without a Bose amp or a Factory amp. This ANC bypass harness plug in at the GM ANC module. We de...

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Elite Bose Factory Amplifier Loopback Harness Accessory

LLJ Customs Car Audio Fabrication
Original price $245.00 USD - Original price $370.00 USD
Original price
$245.00 USD - $370.00 USD
$245.00 USD - $370.00 USD
Current price $245.00 USD
Out of stock

The Elite 6ch Bose Loopback Harness Accessory was specifically designed to work and plug into the factory amplifier, making the process of installi...

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FORD Sync 4 Elite harness base connector 2019-2025

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
In stock

Our versatile Ford Elite Base Connector is compatible with a range of Ford vehicles including the F250,F350, Mustang, Explorer, and more without...

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Silverado pickup amp rack 2014-2019 12"

LLJ Customs Car Audio Fabrication
Original price $50.00 USD - Original price $60.00 USD
Original price
$50.00 USD - $60.00 USD
$50.00 USD - $60.00 USD
Current price $50.00 USD
Out of stock

The Silverado/Sierra Pick-up amp racks are not just the first of their kind ,they are also the best. Our amp racks are designed to fit into place,...

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Chevy/GMC 8 inch speaker door adapter 2014-2024

LLJ Customs Car Audio Fabrication
Original price $65.00 USD - Original price $65.00 USD
Original price
$65.00 USD
$65.00 USD - $65.00 USD
Current price $65.00 USD
In stock

GM/GMC 8" inch speaker adapter is a perfect factory replacement. This will allow you to upgrade from the factory 6x9 speaker to an aftermarket sub...

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Chevy work/custom/elevation trim vehicles with 4" or 7" Screen Elite harness base connector

LLJ Customs Car Audio Fabrication
Original price $60.00 USD - Original price $60.00 USD
Original price
$60.00 USD
$60.00 USD - $60.00 USD
Current price $60.00 USD
Out of stock

Our 7" Chevy harness is designed to work with GM/GMC vehicles like a Traverse with a 7" screen or a Silverado with the Work Truck, Elevation or C...

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ANC bypass harness GMC vehicles W/ UQS,UQP,UQA,UQF RPO Code 2021-Up

LLJ Customs Car Audio Fabrication
Original price $15.00 USD - Original price $15.00 USD
Original price
$15.00 USD
$15.00 USD - $15.00 USD
Current price $15.00 USD
In stock

This GMC Buick ANC bypass harness was designed for vehicles that have the factory Bose amplifier and an RPO code of  UQA,UQF,UQS,UQP. This chevy AN...

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GM Chevy T-harness Black/Gray Connectors 2018-2024 (Non-Amplified) R2R

LLJ Customs Car Audio Fabrication
Original price $240.00 USD - Original price $240.00 USD
Original price
$240.00 USD
$240.00 USD - $240.00 USD
Current price $240.00 USD
In stock

Our Chevy Black/Gray T-Harness allows you to add any aftermarket subwoofer to the Chevy/GMC/Cadillac Audio system in minutes. Using the Chevy/G...

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Bose Wirenator OEM Amp Bypass with 20ft Lead - for 2013-2019

LLJ Customs Car Audio Fabrication
Original price $85.00 USD - Original price $85.00 USD
Original price
$85.00 USD
$85.00 USD - $85.00 USD
Current price $85.00 USD
Out of stock

Our GM Bose Wirenator OEM Amp bypass harness lets you keep using the factory wires already running to your speakers, with an after market amp or h...

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Chevy GMC subwoofer T-harness Aqua/Tan 2019-2024 (None amplified) R2R

LLJ Customs Car Audio Fabrication
Original price $240.00 USD - Original price $240.00 USD
Original price
$240.00 USD
$240.00 USD - $240.00 USD
Current price $240.00 USD
In stock

Chevy Aqua & Tan T-Harness allows you to add any aftermarket subwoofer to the Chevy/GMC/Cadillac Audio  system in minutes. Using the Chevy/...

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Ford sync 3 T-harness (None amplified) R2R 2011-2020

LLJ Customs Car Audio Fabrication
Original price $240.00 USD - Original price $240.00 USD
Original price
$240.00 USD
$240.00 USD - $240.00 USD
Current price $240.00 USD
In stock

The Ford R2R T-Harness allows you to add any aftermarket subwoofer to the ford sync system in minutes. Using the Ford T-Harness with an LOC 2ch L...

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GM/GMC T-harness with 8" or select 4" screen's (Without Bose) R2R 2014-2018

LLJ Customs Car Audio Fabrication
Original price $240.00 USD - Original price $240.00 USD
Original price
$240.00 USD
$240.00 USD - $240.00 USD
Current price $240.00 USD
In stock

The Chevy/GMC R2G T-Harness allows you to add any aftermarket subwoofer to the Chevy/GMC system in minutes. Using the Chevy/GMC T-Harness with an...

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Industry leaders or thieves?

Stolen designs

For years people like CAF and 5STAR said you HAD to pull new speaker wire, then we showed up and now they say loops are the way. Don't trust people who copy others and try to take credit.

The year was 2018

Before the solutions were even needed we had them. It wasn't until 2022 that PAC Audio and Metra would have to backstep and steal our design to stay in the game.

The SCAM that is PAC Audio

The amp-pro was PACs first try to steal our ideas. It failed so bad they had to steal our ANC bypasses to make the amp-pro (2019) work better. (pic taken 2017)

12v Knowledge block

What Is "High Level" or "Low level" ?

What Is "High Level" or "Low level" ?

High level: AKA Speaker level is an amp that can handle an input voltage of 8-40v. This high output is common in factory amplified vehicles or where the
max voltage of a head unit is more than 10v. This is normally identified by a pigtail connection point or via the RCA on the amplifier (must check user manual to verify). Some amps have a switch for this. NOT all amps have this feature.

Low Level: is 0-8v of signal voltage. This is most commonly found in aftermarket head units or other aftermarket units that use can-bus. Most passive LOC units output 0-5v, so they are considered a low level and are normally RCA to RCA. Modern day ACTIVE LOC units can output 0-10v of signal.

In conclusion an LOC works as an in-line filter that lets you control the signal, its intensity and in some cases the playable frequency range.

If your amp takes a high level and it is within the vehicles factory output range then you don't need an loc unit and can wire in and out of your amp directly. In some Fords the signal can be flattened at the OBD2, further simplifying the installation.

Wavtech Units

Automotive Amp Racks

We created the Automotive Amp Rack

We created the Automotive Amp Rack

to give customers a secure place to mount their equipment without damaging their vehicles and having the ability to build and test everything outside of the vehicle. Choosing durable materials like ABS, HDPE, Acrylic and always using factory bolts was our mission.

This product has now turned into an upsell by shops and copy-cats like 5star and car audio fabrications on YouTube to be sold as some type of beauty product. Shops are using cheap materials like expanded PVC board and charging customers a premium price for doing something they should have been doing all along. Your choices are get robbed, or screw holes and water leaks.

They do not represent what our products are and we don't appreciate the theft of our products and ideas being used to steal from customers.