I am new to this also. I just bought a 99 Venture and am in the process of testing the intercom system. I purchased a 6 ft. 5pin din cable with male fitting on both ends from Radio Shack and cut it in half for use on the front and rear. The speaker wires are bare, yellow and black on this cable (pins 2, 5, 3). Sound works fine with this connection. I haven´t been able to get a mic to work yet, not sure if the problem is the mic or the connection or the system. Haven´t found any info on how the system is supposed to work. When the talk button is pressed the audio does not turn off with a mic connected to front and speakers connected to rear. Maybe it needs 2 complete headset connections to function correctly. For your situation you should be able to wire in helmet speakers and have it work fine.