Alpine radio swatch . What are the additional connectors for?

I am switching over my alpine head unit from a 2002 facelift discovery 2. My new modern alpine unit accepts the two original connectors and the main aerial thereby allowing it to power up and work. There are a further 3 separate connect blocks on the unit , far left if you are looking direct on at the unit, which I have no where for them to connect to. I notice that the sub does not work either. Any help would be appreciated. I,m not even thinking about the steering wheel connections yet, could this be them?

What model is it? It could be for a cd changer. As for the sub have you wired the remote cable to the stereo?

I haven't wired the remote cable to the stereo as I was unable to identify what it looked like. Is it possible that those additional connectors are the steering controls and the disc changer? I,m a bit slow when it comes to all things cars but learning as I go a long.

The sub won't work without a live connection. On the stereo it should be a blue cable but usually marked with 'rem' if you have the user manual all will become clear as there's wiring diagrams in there.

Cheers. I will look it up.