My 2006 Wing stereo system works fine with the headset until I turn the intercom on. If I honk the horn I get static through the headset speakers. Anyone else have that problem? Is there a service bulletin?
Ron didn't tell you the full story. It is likely coming from the CB and very common. The CB is actually working as it should.
It detects what it sees as a radio signal of sufficient amplitude, and then un-squelches to allow you to hear the received signal. The horn acts like a generator of RF noise, causing what the CB thinks is signal. When the CB unsquelches, it allows the audio noise now to be un-muted.
A very simple fix is to just tighten the squelch setting to desensitize the receiver, or even turn off the CB when you don't use it.