Please help if you can. I am an electrical contractor trying to revive a house that was used as office space for an internet based business. I ripped out a heck of a lot of networking garbage and I've got the phones working but can't get the old intercom system running. Does anyone know if this system needs a module and what it might look like? The speakers have four terminals on the back: 4/3 Alert and 2/1 Tip/Ring. There's also a jumper for Aux. Alert or Ringdown and Ringdown is selected. I must be missing a part of the system because Tip/Ring just gets me a dialtone and 3/4 terminals are just shorted with the button. Any help would be appreciated.