If You Are Using the XC-1380 Wiring Harness and There Is No Sound After Installation, Follow the Steps Below to Resolve the Issue:
Why is there no sound?
The issue arises because the factory JBL 20-pin harness has two different wiring definitions, which affect how the audio system functions:
- JBL 20-pin connector with ATX+ and ATX- communication signal wires:
In this case, the audio signals from the factory JBL system need to be decoded by our amplifier box. The decoded signals are then sent to the speakers, enabling sound output.
- JBL 20-pin connector without ATX+ and ATX- communication signal wires:
In this scenario, the harness includes a dedicated amplifier control wire. This wire requires a +12V power supply to ensure the factory amplifier functions correctly. Without this power supply, the amplifier will not work, and there will be no sound.
Below are the detailed steps to resolve the issue based on your system setup.
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Sample Images of the XC-1380 Wiring Harness and Amplifier Box:

Scenario 1: JBL 20-pin Connector with ATX+ and ATX- Communication Signal Wires
Below is the factory pin configuration diagram and the corresponding solution.
Factory JBL Head Unit Diagram (with ATX+ and ATX-)

If your factory head unit has this configuration, please follow the steps below.
- Open the “Radio” application on the head unit, locate the settings (gear icon), and turn on the “RDS” switch.

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- At this point, test if the sound is working properly. If there is still no sound, check if the blue wire on the 16-pin connector has a +12V supply. This wire needs to provide +12V to the amplifier box to ensure the JBL system functions correctly.

If there is no +12V supply, cut the blue wire on the amplifier box in the middle and connect it to the red wire.
Warm Reminder: After connecting the wires, ensure there are no exposed wire ends. Use electrical tape or a clip to wrap and secure the connection to prevent short circuits.
Refer to the diagram below for proper wiring.

Scenario 2: JBL 20-pin Connector Without ATX+ and ATX- Communication Signal Wires but With an Amplifier Control Wire
Below is the factory pin configuration diagram and the corresponding solution.
Factory JBL Head Unit Diagram (Without ATX+ and ATX- but With an Amplifier Control Wire)

This issue occurs because the factory amplifier control wire corresponds to an empty pin on our adapter harness, resulting in the factory amplifier not receiving the proper voltage, which causes no sound output.
Refer to the diagram below for details.
Solution: As shown in the marked diagram below, the left image is the factory 20-pin male connector. Connect Pin 3 (purple wire) from the factory harness to the red wire on our head unit’s power cable

Please follow the above solution to resolve the no-sound issue. If you encounter any other problems during use, please feel free to contact us at any time.