Some days I just hate boats. So Robert/Good Vices graciously made me a good deal on his three SafeTAlert 12v detectors. Oddly exactly the same thing happened. Old ones expired in 2007, but the lights were still green, and they squealed as they should when I hit the test button. I carefully snipped the wires (one at a time...) on the first one. Connected the new one. Nothing happened. Tested the two wires coming out of the wall -- nothing, dead, nothing on the volt meter. And the other two old ones, still screwed to the wall and connected, are also dead now, no green lights. Tested the new detector with a 12v battery, works fine. Checked my fuses, all good. I put a wire tracer on the wire to the first one -- goes up the wall, across the ceiling (also known as the floor at the helm above), and the signal stops dead just under the helm seats. It's a long ceiling/floor sandwich about six feet long. I have a fish tape and could pretty easily run a new pair of wires, but since it's either a blown, inaccessible, in-line fuse or maybe a bad butt connection inside the floor, I don't know which red wire (of about 20) that come into the helm pod serves the CO detectors, so I don't know which one to remove at the helm end. The fact that all three detectors are dead now makes me think they must all be wired on the same circuit. I hate to be beaten by electrical problems, and I don't like dead wires messing up my neat bundles inside the walls and floors, but this is starting to feel like my battle to keep the old Norcold refrigerator alive. At some point I just have to admit defeat and buy modern, battery-operated detectors and be done with it. Life is short, I have 43 other things on my to-do list.