Post Edit: You have to have either the Yamaha branded 7-pin cords, or as some are using, the Harley-Davidson 7-pin hook up cords,....using Honda GoldWing 5 pin cords won't work, if having had a prior GoldWing.
For the Intercom, you have to turn it on, under COMMS, and you also have to set both rider and co-rider's helmets to CHECKED in the activation boxes for each under AUDIO OUTPUT, in the Communication sub-section. Then, finally, you raise the volumes of each (my wife and I use around 7-11)
You have to press your CB/Intercom trigger switch (on the front of the left handle bar pod, and your co-rider needs to press once, her, or his left side communication button. The Passenger/Co-Rider button can be used to press once, the Intercom is live, press again, and the Intercom session is ended, even though the Intercom is activated within your COMMS menu.
This is one feature that my old 2008 Wing never had, that if the Intercom was live, the talk circuit was always live, even if you didn't want it to be. With the SVTC, you can have the Intercom communication hot, but just not have open communication with the Co-Rider, until you do wish to open channel, or she/he wishes to open channel.
So, all of the above needs to be in play. It took my wife and I a couple of uses, before it is now old hat for us. The most important thing, is that you make sure under AUDIO OUTPUT, that both helmet selections are 'on', under the Communication heading. Then...you go to VOLUME, and adjust that for the each of you. The SVTC is so sophisticated, that all volume functions can be independently set n' forget for each saddle station. It takes some time to curve-learn, and set up how you and your Co-Rider will like things set. But, what a great bike, that this was allowed you...and not one volume for all...!