Refitting A standard stereo

[gazcicini]

I am trying to fit a standard stereo from a Golf GTI into my Audi Coupe. The wiring loom looks the same and its all on ISO plugs but when I plug it in the red security light flashes and when I try to power up the display flashes blue then goes grey again. Is this a security feature or have I got my wiring wrong. I have positive, negative, and illumination wired up and nothing else. Do I need to connnect more wires as was in my Golf? Any help would be appreciated.

[mobitune]

I don't know enough about this to give you an answer, but it may be worth investigating if both or either cars are CAN bus

If the Golf was (mkV) then you will need an adaptor cable if your Audi isn't

[gazcicini]

"CAN bus"???

The golf was W reg and the Audi is 1996. I have had a look at the ISO connectors in ********* and they seem the same. I am just thinking that teh stereo has reset or something where it was disconnected from the battery?