During my first big cruise this summer, on occasion, the A-B would attempt to start (run), and then we'd hear an alarm beep, and it would shut down. It would then retry and the same thing would happen, and so on. And then, after a while, it would be O.K. I don't think it was correlated with low voltage on the house bank. I tightened the terminals for the power wires connected to the control unit, and I don't think it has happened since. What is it? Thanks, jv