You can get additional intercoms working if you want to. It may require a little wire wrapping, but it can be done.

Also 3&18 should be "A" Battery & Ground, not "B" - otherwise the ICMs will have a hum on them.

Sometimes battery was lifted from those pins to allow Music on Hold to be installed on line cards.

Good luck on your project!


Sam

"Where are we going and why are we in this hand basket?"