Elite Harness system layout

Bose factory amplifier Base Harness Connector for GM | GMC 2014-2019

In stock

Key Features

  • The base connector is what connects to the factory audio source. EX: radio, factory amplifier)
  • Can be used as a T-harness or a Loopback harness
  • Abrasion resistant loom
  • Vehicle OEM connectors
  • Constant 12v +/-
  • Retains ALL Factory functions as they are
  • Designed, Tested and Hand-built by us.
  • 5 year warranty guaranteed

Starting at :

$65 USD
This product is only available through our Custom Elite Harness Builder Program. (CEHBP)
Email: Support@lljcustoms.com
Text or schedule a call: 602-320-7004

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 the factory Bose amp, including Cadillac and Buick. It comes available in both style of harnesses, a T-Harness and a Loopback Harness. If you are planning on adding a sub to your Sierra we offer our T-Harness. You can add an LOC unit, like a Wavtech LinkDQ, for a full plug and play set up.

If you’d like to amplify your doors or add multiple amps to your Silverado we offer our Loopback Harness. This was designed to allow you to keep using the factory wiring, NO cutting, NO splicing. Add an amp quick and simple without ruining your vehicles wiring or voiding your warranty.

150% Plug and Play

  • Some Bose amps have a GRAY connector instead of a BLACK connector. This harness will still work with your gray connector. It will have an offset tab, we will cut one of the tabs on our harness to fit your vehicle. If your harness has both side tabs please note the LEFT tab needs to be trimmed. 
  • Harness ordered with an LOC/Processor includes a remote turn on cable. 

Looking to add a sub? Keep the install simple with your Bose T-Harness:
  • The Bose T-Harness will plug in at the Bose amp
- In a truck at may be behind the rear seat
- In a car/sedan it may be under the center console next to the gas pedal or in the trunk.
  • The LOC that was ordered with your harness, or your own you attached, will provide RCA out and Remote turn on.
- Run your RCA wires from the output on the LOC to the RCA input on your mono amp.

- Run your remote turn on wire (blue wire) from the LOC unit to the mono amp.
  • Lastly run your power wire to your amp from the battery and a ground wire within 18 inches or shorter.
- The chimes are not affected in any way when adding subs.

All done! 

5 year LLJ Customs warranty badgeInstallation Video

Our harness throughout the years has evolved into what we call, and are currently in the process of patenting, our Elite Series Harness. This option is an all-in-on solution for the ultimate DIY’er.. After 7 years, developing our own wire and combining LOC’s, processors, DSP’s and companies like Audio Control and Rockford Fosgate, who offer amplifiers with a high level input signal. By combining these top shelf solutions for the 12V market you can get an entire system upgrade at the same price of a factory head unit upgrade alone.

  When choosing an LOC it is important to know if one is even needed. Especially if you already have your own equipment. Look at what the parameters of that equipment are and if the amp takes a high level. For example some mono-amp’s cant take above 5V of signal input. When using a Wavtech Link2 or an Audio Control LC2i Pro you want to verify the signal output does not exceed what the amp can take.

 It is recommended to verify if the vehicle has Active Noise Cancelation (ANC) before placing an order. You can do so by checking for the microphones in the headliner, above the rear seat. With aftermarket subs or speakers the ANC microphones create a feedback. To avoid the humming or “pop-like” sound from happening we offer our Bose ANC Bypass. This plugs into the Bose amp as the diagram in the pictures will show.

This unit will work with all GM vehicles Equipped with a BOSE OEM amplified system from 2014-2021. Including:


  • Encore 2017-2019
  • Enclave 2018-2018
  • Envision 2016-2018
  • Lacrosse 2014-2018
  • Regal 2014-2018
  • Blazer 2019-2021
  • Camaro 2016-2019
  • Cheyenne 2014-2019
  • Colorado 2015-2020
  • Corvette 2014-2020
  • Cruze 2016-2018
  • Equinox 2015-2019(2012-2015 with pioneer system)
  • Impala 2014-2021
  • Malibu 2016-2021
  • Suburban 2015-2021
  • Silverado 2014-2022
  • Traverse 2018-2021
  • Tahoe 2015-2020
  • Volt 2016-2019
  • Acadia 2017-2021
  • Canyon 2015-2019
  • Sierra 2014-2021
  • Terrain 2018-2021
  • Yukon 2015-2021


  • Escalade 2015-2019
  • CT6 2016-2020
  • CTS 2014-2019
  • XT5 2017-2019
  • XTS 2013-2017
  • SRX 2013-2018

**6ch T-Harnesses or harnesses with units currently have a 30 business day lead time, 2ch T-Harnesses with no unit currently have a 2-9 business day lead time. **

 **Loopback Harness currently have a 30-35 business day lead time, this timeframe can vary depending on customizations . **

Please verify the connector in the vehicle BEFORE placing an order. All Base Connectors that need to be returned, refunded or canceled due to the connector not being verified will have a Restocking Fee of $15. The connectors need to be in the exact same condition as they were sent in. Any damage or alterations made will void all exchanges and returns.

Elite T-harness Accessory Options-ETA

-Must Have a Base Connector to use this Accessory (BC)

The question is always what is the difference between the T-harness and the Loopback and the simple answer is, the T-harness is ideal for adding a Subwoofer only/mono amp or in a situation where you plan to run your own wires from the aftermarket amp to your new speakers. More information in the next page.

Elite LoopBack Accessory Options-ELA

-Must Have a Base Connector to use this Accessory

Our Loopback is simply the best option for any installation. Not just do you get the SIGNAL from the factory source unit but it also comes with 12v DC +/- to power your LOC or DSP. It also has a RETURN side that feeds from your aftermarket amps output, back to the factory speaker locations via the factory wires. The Loopback can also be tied together at the end, closing the loop in essence making a T-harness so you can start small and grow without needing to buy more.

Elite GX:500 S.I.K Options

Our S.I.K kits were the first of their kind to ever exists in the 12volt market. A solution long needed but never provided. "You need new speaker wire," was always the answer. That's no longer true. Increase the output and performance of your factory system in under 30 minutes. Our design places the aftermarket amplifier in the middle of your Elite Harness System.

Take the factory signal modify, tune, amplify and right back to the factory speaker locations. The amps we provide as a choice, we have used over the years and know they will work well in the particular function. Meaning all you have to do is plug in connect power and enjoy. Furthermore if you want to add an amplifier for subs we offer the option to add an Active LOC to your harness for future integration. Check out more below.

-Most Have a Base Connector to use this Accessory

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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 then 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 future.

Low Level : is 0-8v of signal voltage. This is most commonly found inaftermarket 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 lest you control the signal, its intercity 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 dont need an loc unit and can wire in and out of your amp
directly. In some fords the signal can be flattened at the OB2 furthering the simplification of the installation.

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