ISO adapter harness for fitting a new stereo in an Audi A3, A4, A6 or TT with an original BOSE or SYMPHONY amplified audio system with ISO connectors are the back of the head.

The harness has a built in CANbus ignition interface for plug and play installation. Also provides illumination. Use with item 21-120 for antenna FM connection.

This harness adapts from the original ISO and Mini ISO connectors at the back of the head unit to standard aftermarket ISO connectors. The harness has a built in high to low level audio adapter to drop the speaker outputs from the new head unit to a low line level signal to work with the original amplifier in the car. The high to low level adapter has 4 dials to individually set the levels of each audio channel to give perfect sound quality.

Some early Audi TT cars will have CANbus wires at the back of the radio but do not carry the CANbus ignition data.

Harness Adaptors

Connect the head unit to the original radio connector without the need to cut any of the existing wiring.

TECHNICAL NOTE

• CAR AUDIO FITTING ACCESSORIES ARE SOLD WITH LIMITED INSTRUCTIONS. 
• SOME KNOWLEDGE OF CAR AUDIO INSTALLATION IS HELPFUL IN CASE A MODIFICATION IN SOME RARE CASES MAY BE NECESSARY OR NEEDED.

If in doubt please email us with your vehicle details and we will confirm what you require.

Please make sure that is the correct Wiring Harness for your car by firstly checking to see if your make, model and year of car is listed in the description. Secondly by checking to see if the Shape in the picture listed is the same as you have in your vehicle. We try to provide upto date information as possible. If you are unsure please contact our Customer Service and we will be happy to help you.