I was hooked up to my generator yesterday, just to check things out. And this "alarm" sound started coming out of the radio, while it was off. But it was not out of the speakers. Just the radio itself. I unplugged the camper and it stayed on. Then I removed the radio and unplugged it from the wire harness, and it was still ringing for about 5-10 secs, and then went off. When I plugged it back, it came back on... I removed the 12volt fuse and it did the same thing. When I put the same fuse back in, it was not ringing. Since then no ringing. Everything works fine including the radio itself... what was this and what caused it???
2007 GMC Duramax
2007 VR1 310BHS