Quoted from Shredso:
Not sure if this will help at all as mine is not original and has an aftermarket speaker, but it works. The stray barrel connector is not connected to anything on mine.
[quoted image][quoted image]
Thanks for the photos! Your photo definitely shows what type of inline/barrel connector SHOULD be on there, lol, so that helps.
Your J504/J505 connections look different than mine but I wonder if that's because your setup is aftermarket as you mentioned. Very curious.