Here is the stereo radio wiring information for your 2005 Audi B6 / B7 A4 with the standard, symphony, or Bose systems. It will be useful when installing an aftermarket radio, sound stereo system, or other automotive accessories. Make sure to grab the appropriate tools to test all the wires in your A4. Please check it over and use it as a GUIDE to help you locate the appropriate wires. This schematic is provided free of charge and may not be 100% accurate. Failure to properly test all the wires may lead to vehicle or bodily damage. All information is provided as-is and accuracy is not guaranteed.

If you find any conflicting info please leave a comment with what you found in your Audi B6 / B7 A4. If you don’t see the wiring diagram you need comment and we will try to add it ASAP. Thanks for looking!

Keep in mind if you are installing a new radio you may need the radio removal  keys, the wiring harness, the antenna adapter, and the mounting kit as well. See the links below to purchase these items.

2005 Audi A4 Car Audio Stereo Radio Wiring Diagram Schematic Colors

Car Radio Constant 12v+ Wire: Red/Blue
Car Stereo Ground Wire: Brown
Car Radio Ignition Switched Wire: Not available Grab @ Fusebox

Car Stereo Dimmer Wire: Gray/Blue @ Radio with Nav Only or Cigarette Lighter
Car Radio Illumination Wire: Gray/Blue @ Radio with Nav Only or Cigarette Lighter
Car Stereo Power Antenna: N/A
Car Radio Amp Turn On Wire: White @ Radio

Left Front Speaker Wire (+) Positive: Brown/Green
Left Front Speaker Wire (-) Negative: Blue/Yellow
Right Front Speaker Wire (+) Positive: Brown/Blue
Right Front Speaker Wire (-) Negative: Green/Blue

Left Rear Speaker Wire (+) Positive: Brown/Yellow
Left Rear Speaker Wire (-) Negative: Red/Yellow
Right Rear Speaker Wire (+) Positive: Brown/Black
Right Rear Speaker Wire (-) Negative: Red/Green

Center Channel Speaker Wire Positive / Negative: Tied in with front speakers.

Subwoofer Speaker Wire Positive / Negative: Red/Gray Brown/Gray @ Amp

Front Speaker Size: N/A

Rear Speaker Size: N/A

Amp Amplifier Location: Passenger side of trunk behind carpet
Radio Removal: VW / AUDI / MERCEDES Keys

AFTERMARKET RADIO MOUNTING KIT SINGLE OR DOUBLE DIN:

Audi A4 02 – 08 SDIN – DDIN kit (Matte Black)

AFTERMARKET RADIO WIRING HARNESS:

Metra 70-1787 Radio Wiring Harness for VW/Audi Bose Integration 1993-2007

AFTERMARKET RADIO ANTENNA ADAPTER:

Metra 40-VW54 VW Amplified Antenna Adapter

STEERING WHEEL CONTROLS ADAPTER:

Metra Axxess ASWC-1 Universal Steering Wheel Control Interface

RECOMMENDED TOOLS FOR THE INSTALL – SAME ONES THE PROS USE!

– Klein Wire Cutters / Crimpers

– Gardner Bender Auto Wire Stripper

– Dash Removal Plastic Pry Tools

– 3M Electrical Tape

– Install Bay Butt Connectors

Here is the stereo radio wiring information for your 2004 Audi B6 A4 with the standard, symphony, or Bose systems. It will be useful when installing an aftermarket radio, sound stereo system, or other automotive accessories. Make sure to grab the appropriate tools to test all the wires in your A4. Please check it over and use it as a GUIDE to help you locate the appropriate wires. This schematic is provided free of charge and may not be 100% accurate. Failure to properly test all the wires may lead to vehicle or bodily damage. All information is provided as-is and accuracy is not guaranteed.

If you find any conflicting info please leave a comment with what you found in your Audi B6 A4. If you don’t see the wiring diagram you need comment and we will try to add it ASAP. Thanks for looking!

Keep in mind if you are installing a new radio you may need the radio removal  keys, the wiring harness, the antenna adapter, and the mounting kit as well. See the links below to purchase these items.

2004 Audi A4 Car Audio Stereo Radio Wiring Diagram Schematic Colors

Car Radio Constant 12v+ Wire: Red/Blue
Car Stereo Ground Wire: Brown
Car Radio Ignition Switched Wire: Not available Grab @ Fusebox

Car Stereo Dimmer Wire: Gray/Blue @ Radio with Nav Only or Cigarette Lighter
Car Radio Illumination Wire: Gray/Blue @ Radio with Nav Only or Cigarette Lighter
Car Stereo Power Antenna: N/A
Car Radio Amp Turn On Wire:  White @ Radio Pin 6 in 20 Pin Plug

Left Front Speaker Wire (+) Positive: Brown/Green
Left Front Speaker Wire (-) Negative: Blue/Yellow
Right Front Speaker Wire (+) Positive: Brown/Blue
Right Front Speaker Wire (-) Negative: Green/Blue

Left Rear Speaker Wire (+) Positive: Brown/Yellow
Left Rear Speaker Wire (-) Negative: Red/Yellow
Right Rear Speaker Wire (+) Positive: Brown/Black
Right Rear Speaker Wire (-) Negative: Red/Green

Center Channel Speaker Wire Positive / Negative: Tied in with front speakers.

Subwoofer Speaker Wire Positive / Negative: Red/Gray Brown/Gray @ Amp

Front Speaker Size: N/A

Rear Speaker Size: N/A

Amp Amplifier Location: Passenger side of trunk behind carpet
Radio Removal: VW / AUDI / MERCEDES Keys

AFTERMARKET RADIO MOUNTING KIT SINGLE OR DOUBLE DIN:

Audi A4 02 – 08 SDIN – DDIN kit (Matte Black)

AFTERMARKET RADIO WIRING HARNESS:

Metra 70-1787 Radio Wiring Harness for VW/Audi Bose Integration 1993-2007

STEERING WHEEL CONTROLS ADAPTER:

Metra Axxess ASWC-1 Universal Steering Wheel Control Interface

RECOMMENDED TOOLS FOR THE INSTALL – SAME ONES THE PROS USE!

– Klein Wire Cutters / Crimpers

– Gardner Bender Auto Wire Stripper

– Dash Removal Plastic Pry Tools

– 3M Electrical Tape

– Install Bay Butt Connectors