Swc and radio wiring in 2015 313

Hi guys, wondering if I can get some help because either I have the only sprinter wired this way or no one has documented this yet. Or my googling and search skills are poor.

Anyway, was replacing the radio with aftermarket, on the harness I have identified, speaker cables (all brown with a line of green, purple, blue orange) then the pink Fakra to USB connector. I see the wires to the microphone (purple and grey with a clear cable too) I see the aux 3.5 connection (yellow, brown, black and clear cable)

What's confusing me is I have two thick red/black 12v, neither seems switched both live all the time (so no ignition power?)

Then I have large brown, assuming ground.

Then a thin brown and a thin brown and red. What are these? And am I right with the other assumptions?

Also with a multimeter and no keys in ignition both red/black cables show 12.6v and the thin brown shows 11.5v with keys in or engine running both black and red cables read 14.6 and the thin brown runs 4.1

Will post photos for clearer look in a sec

Gore said:

Then a thin brown and a thin brown and red. What are these?

Click to expand...

Are the thin Brown and Brown/Red wires twisted together? If so they are the CAN signal to control the radio.

There is a recent thread where an owner bought a 'converter' to control an aftermarket radio.

Keith.

No not quite, here is what it looks like;

https://i1189.photobucket.com/albums/z433/ggore219/sprinter2015.jpg