XTRONS Car ISO Harness Adapter Cable for Audi A3 A4
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Product description
This ISO harness adapter cable from XTRONS converts high to low impedance to restore clean audio to rear speakers after fitting an aftermarket Android Auto car stereo. It helps resolve issues like no sound or static from the rear channels when your head unit and vehicle wiring do not match, making it a useful accessory for owners of Au-di A3 and A4 models that use a 40-pin harness.
Key Points

The adapter plugs between the car’s original 40-pin harness and an aftermarket head unit, allowing signal conversion so factory speakers receive an appropriate output level. It is compatible with XTRONS head units and other brands that accept the same 40-pin connector, according to the manufacturer. For many installers, this cable avoids cutting factory loom wires or fitting separate amplifiers, saving time during installation. Note that it is intended for signal conversion and will not add amplification beyond what the head unit provides, which may be a consideration if your system needs more power.


Technical Specifications

- Name: XTRONS Car ISO Harness Adapter Connector Cable
- Compatibility: 40-pin harness systems, models such as Au-di A3 and A4.
- Function: High-to-low impedance converter for rear speaker outputs.
- Suitable head units: XTRONS and other Android Auto stereo players using 40-pin connection.
- Warranty: 3 months, with customer support via the seller’s email.
How to Use It



Installation is straightforward for those comfortable with basic car audio wiring. Disconnect the vehicle battery first, unplug the factory 40-pin harness and insert the adapter between the harness and the aftermarket head unit. Once connected, test the rear speakers before completing the installation to confirm that the static or lack of sound has been resolved. If wiring colours differ, consult the head unit manual or a wiring diagram; incorrect connections can result in phase issues or reduced performance.
Practical Tips

For a neat finish, secure the adapter and any excess cable with cable ties and tuck it away to prevent interference with moving parts. If you notice low volume despite clear sound, consider that the converter lowers impedance rather than increases power, so a separate amplifier may still be needed for higher output. According to the manufacturer, XTRONS provides professional customer support for pre- and post-sale queries, which can help if the unit does not behave as expected or if you need guidance on compatibility.
This description uses the model reference XTRONS Car ISO Harness Adapter Connector Cable to highlight the exact product. A possible limitation is that compatibility depends on the exact 40-pin layout used by some vehicles, so double-check the connector type before assuming fitment.
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