Panel 301: how/where is the radio connected?

[Krumelur]

I'm looking at the wiring chaos behind my 301 panel and am busy cleaning it up.
I don't understand how the button for "Radio" works (the one with the notes). On the board there are plenty of printed labels, like "Dusche" (shower). But I cannot find anything that seems to relate to the radio.

What I did find however is a set of three wires (black, dark purple, and light rose) which feed into a thick wire branch labelled "Lichtkabel" (light cable). If I press the radio button, the purple wire receives +12V, the black is minus.
I don't know what the rose one is about, though.

There are numbers on the wires: purple = 12, rose = 9+

On the board I can see (centered) two bigger connectors. Both of them contain wires with the colors I'm facing. They are labelled "Achtern" (stern) and "Licht" (light).

Why is the radio connected to "Licht"?
What is the rose wire for?
Why is there no clicking relay sound when pressing the radio button?

[Jeffatoms]

Just for clarity, I'm assuming you are talking about the entertainment radio, not the VHF.  Yes, on mine it is indicated by the broadcasting antenna.  The trick to make it work (I believe) is most car stereo radios have two positive leads; one, the on/off is at the panel but there is also an always on that is used to power the presets and the time.  Often, this one connects directly to the positive post on the battery.

[Mirror45184]

On the Manuals page https://bavariayacht.org/forum/index.php/topic,1541.0/topicseen.html there is a Panel 301 manual. This has a list of all connections.