1. Introduction
The PAC L.O.C. Pro Advanced Audio Integration T-Harness (Model LPHGM51) is designed to simplify the integration of aftermarket audio equipment with your vehicle's factory radio system. This vehicle-specific T-harness provides all necessary high-level inputs and speaker outputs, allowing for the addition of aftermarket amplifiers or signal processors while retaining the original factory radio.
Important Note: This product is specifically designed for OEM non-amplified systems and is not for use in vehicles with a factory amplifier.
2. Compatibility
The LPHGM51 T-Harness is compatible with select 2018 to 2023 non-amplified GM vehicles. Please verify your vehicle's compatibility before installation.
Compatible Vehicles (All Trim Levels, Non-Amplified Systems):
- Buick: Envision 2017, LaCrosse 2016, Regal 2014-2015
- Cadillac: ATS 2015-2016, CTS 2014-2015, Escalade 2015, SRX 2015-2016, XT5 2017
- Chevrolet: Camaro 2016-2018 (with 8-in. screen IO5/IO6), Colorado 2015-2016, Cruze 2016-2017, Impala Non-Classic 2014-2016 (with 8-in. screen IO5/IO6), Impala 2017-2019 (with 8-in. screen IO5/IO6), Malibu Non-Classic 2016, Malibu 2017-2018, Silverado 2014-2017, Silverado 2018 (with 8-in. screen IO5/IO6), Silverado Classic 2019 (with 8-in. screen IO5/IO6), Silverado HD 2015-2019, Sonic 2017, Spark 2015 and 2018
3. Setup and Installation
3.1 What's in the Box
- PAC L.O.C. Pro Advanced Audio Integration T-Harness (LPHGM51)
- User Manual
3.2 Pre-Installation Considerations
- Safety First: Always disconnect the vehicle's negative battery terminal before beginning any electrical installation to prevent short circuits and damage.
- Professional Installation Recommended: If you are not familiar with car audio wiring and vehicle disassembly, professional installation is highly recommended.
- Tools Required: Basic tools such as wire strippers, crimpers, electrical tape, zip ties, and a panel removal tool may be necessary.
- Factory Amplifier Check: Confirm your vehicle does not have a factory-installed amplifier. This harness is incompatible with amplified systems.
3.3 Installation Steps
- Access the Factory Radio: Carefully remove the necessary trim panels and components to gain access to the back of your vehicle's factory radio. Refer to your vehicle's service manual for specific instructions.
- Disconnect Factory Harness: Locate and disconnect the main wiring harness from the back of the factory radio.
- Connect T-Harness: Connect the male end of the LPHGM51 T-Harness to the factory radio. Then, connect the female end of the LPHGM51 T-Harness to the vehicle's factory wiring harness that was just disconnected.
- Wire Aftermarket Equipment: The T-harness provides labeled wires for high-level audio outputs (e.g., front left speaker +, front left speaker -, etc.). Connect these wires to the corresponding inputs on your aftermarket amplifier or signal processor. Ensure all connections are secure and properly insulated.
- Secure Wiring: Route and secure all wiring to prevent pinching, chafing, or interference. Use zip ties to keep cables tidy.
- Test System: Before reassembling the dashboard, reconnect the vehicle's negative battery terminal and test the audio system to ensure proper functionality of both the factory radio and aftermarket components.
- Reassemble: Once confirmed working, carefully reassemble all removed trim panels and components.
Figure 1: Overview of the PAC L.O.C. Pro Advanced Audio Integration T-Harness, showing the main connectors and individual speaker wire outputs.
Figure 2: A closer view of the PAC L.O.C. Pro T-Harness, illustrating the connection points for factory and aftermarket wiring.
4. Operating the System
Once the PAC L.O.C. Pro Advanced Audio Integration T-Harness is correctly installed, its operation is seamless and integrated with your vehicle's existing audio system. The harness functions as an intermediary, providing high-level audio signals from your factory radio to your aftermarket audio components without altering the factory radio's functionality.
- Your factory radio will operate as normal, controlling volume, source selection, and tone.
- The audio signals are passed through the T-harness to your aftermarket amplifier or signal processor, which then processes and amplifies the sound for your aftermarket speakers.
- Adjustments to sound quality (e.g., bass, treble, balance, fader) will primarily be managed through your factory radio, while specific amplifier settings (gain, crossover) will be managed on the aftermarket equipment.
5. Maintenance
The PAC L.O.C. Pro Advanced Audio Integration T-Harness is designed for durable, long-term, and maintenance-free operation. No routine maintenance is required for the harness itself.
- Connection Integrity: Ensure all connections made during installation remain secure and free from moisture or physical damage. Loose connections can lead to intermittent audio or signal loss.
- Wiring Inspection: If you experience any audio issues, a visual inspection of the wiring for signs of wear, fraying, or damage is recommended.
- Environmental Protection: Keep the harness and connected components away from excessive heat, moisture, and corrosive substances.
6. Troubleshooting
If you encounter issues after installing the LPHGM51 T-Harness, refer to the following troubleshooting guide:
6.1 No Audio Output from Aftermarket System
- Check Connections: Verify that all connections between the T-harness, factory radio, vehicle harness, and aftermarket equipment are secure and correctly seated.
- Aftermarket Equipment Power: Ensure your aftermarket amplifier or signal processor is receiving power and is turned on. Check its power, ground, and remote turn-on connections.
- Factory Amplifier: Double-check that your vehicle does not have a factory amplifier. This harness is not compatible with amplified systems.
- Source Selection: Confirm the factory radio is set to an active audio source (e.g., radio, media player).
6.2 Distorted or Poor Audio Quality
- Gain Settings: Adjust the gain settings on your aftermarket amplifier. Incorrect gain settings can lead to distortion.
- Wiring Integrity: Inspect all audio signal wires for shorts, breaks, or poor insulation. Ensure they are not running too close to power wires, which can cause interference.
- Grounding: Verify that the ground connection for your aftermarket equipment is solid and free of corrosion.
6.3 Intermittent Audio
- Loose Connections: Re-check all harness and wiring connections for any looseness.
- Damaged Wiring: Inspect wiring for any signs of damage or intermittent contact.
7. Specifications
| Attribute | Specification |
| Brand | PAC |
| Model | LPHGM51 |
| Material | Locpro |
| Item Dimensions (L x W x H) | 8 x 8 x 1 inches |
| Item Weight | 4.9 ounces (0.14 Kilograms) |
| Connector Type | GM-specific Connector |
| Wire Diameter | 1.02 Millimeters |
| UPC | 609098900485 |
| Compatibility | Select 2018-2023 Non-Amplified GM Vehicles |
8. Warranty Information
Specific warranty details for the PAC L.O.C. Pro Advanced Audio Integration T-Harness (LPHGM51) are not provided in this manual. For comprehensive warranty information, including terms, conditions, and duration, please refer to the official PAC Audio website or the product packaging.
9. Customer Support
For technical assistance, installation questions, or any other inquiries regarding your PAC L.O.C. Pro Advanced Audio Integration T-Harness, please contact PAC Audio customer support directly. You can typically find contact information and support resources on the official PAC Audio website.
Website: https://pac-audio.com/ (Please check for the most current URL)
