I took the battery to be tested, the posts tested OK, but the threaded pins tested Replace. So I thought, OK this is it, bought a new battery, fully charged, still get the ping. Everything works Shore power, with the battery unattached, no ping. Where is the thermal cut out, what does it look like, can it be reset, would the ping sound if it were "cut out", seems the battery supplies the energy to make the ping sound. The battery is connected correctly. Using Buss 15 amp fuses, could one of these not be breaking when it should, would it be worth changing them all out? What device is making the ping sound, could it be bad, if so how can this be tested? Thanks for your help.