'97 Audi A4 Gamma stereo replace

Hi there!

You should switch the red and the yellow cables that are in loom that came with

your Hu. Most european car manufacturers that uses the so called ISO connector

have reversed ignition logic, which means that the red and the yellow cable are

switched with eachother in the connector inside the car. Altough the connector is ment to be standard

its only the connector fysically that are standard in the meaning that you can only plug it in one way.

There is no standard in the pin configuration.

About your other question.

Either you dont have any rear speakers, or otherwise they are active.

If they are active there is either Bose or Nokia.

Then you use the mini iso (the yellow 6-pin called C1 in the figure below 

or a red 20-pin or a black 20-pin)

See the figure to make it easier to understand (the back of your Gamma headunit).

In the yellow connector:

Pin 1: Line out left rear

Pin 2: Line out right rear

Pin 3: Line out ground (common for all 4 channels)

Pin 4: Line out left front

Pin 5: Line out right front

Pin 6: Remote (common for all 4 individual speaker amps, not always used, sometimes

you use A3, equals pin 3 in the black 8-pin connector)

There should be a sticker on the Gamma headunit that explains all this to you.

In Sweden we use an adapter for about 53 usd that makes it so easier to install.

And also when we buy a new Hu its always end with a female ISO.

You could use this one:

This is Autoleads PC 9401 that fits several Audis.

There can be several to choose from depending on several things for example the voltage on the line out.

See http://www.autoleads.co.uk/installation_db.html for more info.

And if you dont want to cut any cables in your car you can look for an PC 3433 from the same

manufacturer. It will fit your Sony in one end and it has a female ISO in the other!

We have done that ourselves when our customers has bought a Sony from the U.S.

Or you can just buy a Hu from Blaupunkt, they use mini iso.

Good luck!