Batboard

I have a cdm1250 installed in my fire apparatus. Recently a SETCOM intercom/ headset was donated to us. I am trying to figure out how to hook the intercom box up to the radio. I have purchased the plug for the back of the radio. The intercom box has a four wire connector that goes to the radio. I am in need of a drawing or pin connections, so I can hear and transmit thru the headset?

We are a small voluteer department any help would be appreciated!!

Thanks

I know nothing about the headset but here is the radio info you need.

Pin 2 - ext mic audio
pin 3 - PTT
pin 7 - ground
pin 11 - Receive audio flat / filtered configured in CPS.
pin 16 - ext sp audio