There are five wires that come out of the ARC plug what is the 5th black wire for? I think someone said it was some sort of speaker ground? Where does it connect to?
I looked in ARC's instructions and there is no mention of it...all they say is to hook it up to the stock wiring.
Any help would be great....as I would love to get this thing wired up.

 

On my old Road Glide,I connected that wire to the fairing bracket which would be ground.

 

I believe it mentions in the paperwork somewhere that you could ground that wire if you experience a lot of electrical noise. I just left it alone and mine sounded great. I've since switched decks and now use RCA input.

Zach

 

Thanks guys