Been working about 6 months on remodeling my Alumacraft fifth wheel, and all that time it has been plugged into shore power. The cover was off the power panel when I got it, and the fans are there and wired, but I have never heard them come on. Is this normal? If I turn on everything that uses 12v, should they eventually come on? I know this converter is obsolete, but I don't want to replace it unless I have to, but hate to have this thing go out when I'm out in the boonies.