Hi Andrew, I fitted a radio in my +4 GDI, all I did was plug the connector block into the back of the radio and away it went, the power wire is in the block connector.
Ian

The red power lead on the radio could be for supplying power for a power aerial?

Last edited by exbiker; 11/08/16 03:22 PM.
2017 Mercedes Benz SLC 200 AMG.
2019 Mercedes Benz GLA 200 AMG
Now Ex-Mogger!