Revisiting an old problem

Greetings,
Don't you love revisiting your old projects? I am upgrading my head unit on a 2007 OR without JBL. A couple head units ago I had to splice in what believe was PAC SWI-RC steering wheel control adapter. In order to do that you had to splice in a resistor between the yellow and white/purple wire and something I can't remember to this red wire. On the end of the red wire there was a barrel connector splitting it three ways. I am trying to get back to square one/ stock setup to regain steering wheel controls.

I can't remember what I did 10 or so years ago. Cant seem to get a firm understanding of the SWI manual and every pic I have seen so far of the stock plugs does not show these three wires.
There are three empty ports between the two plugs yet no terminals in the connector. Knowing my skill set in those days I don't believe I would have actually removed the terminal from the connector and would have probably just snipped them leaving the terminal in the connector
Any idea where how these three cable were originally terminated and what they do?

 

Ok, was researching last night and the steering wheel controls had has/had its own harness/connector. I now remember chopping and holding onto for a number of years before forgetting what it was and then throwing it out. Anyone have a pin out or know which wire controls what button?