2005 Kenwood Sirus/Wired Remote Setup

Hope summer is going well for everyone. After a late start we are starting to get some time on the boat these last several weeks.

Over the winter I installed an HSE and a cheap EQ that allows for control of the tower vs cabin and sub volume. I have the Kenwood X679 Head Unit and the Sirius controller plugs into the back where a CD changer would go. This is all factory and it was not ordered with a wired transom remote. With the way we use our boat, that would really come in handy so I was looking into what it would take to add one without replacing the head unit. Well you probably guessed that Kenwood does not make these any more, but I have found a couple places that say they have a few left. In my quest, I talked to Kenwood and they said that a Splittler is required for that port on the back so that I could connect both the Sirius and the wired remote. If I recall though, the Sirius unit had a pass through, so I was wondering if someone with this setup or knowledge could tell me if the S220A splitter is required or how their remote is wired in.

Thanks in Advance,

Dave