Need help or advice. I have a G3X with a GTR20R as my number 2 com and The GNC355 as Com 1. I have installed a GMA245R. I programmed it and my problem is that my intercom between the fore and aft position does not work. I do not have ICS mute wired in(not using). the radios work normally. Any ideas? Garmin was noit much help. I verified that the audio and mic jacks are wired correctly. Any help would be appreciated