Originally Posted by David Hendy
If you blew the 30 amp fuse the fan is drawing too much current & is on its way out I'll bet....
Good thinking but not necessarily so. German fuses are a lot like beer cans. If you bend them back and forth enough times they will snap. When current flows through a fuse, it acts like a tiny resistor. The heat produced during current flow causes the fuse metal to flex. As the metal cools it relaxes. This constant flexing back and forth eventually causes the metal in the fuse to snap. In most cases there is nothing wrong with the circuit. All you need to do is replace the fuse with a fresh one, and the flexing begins again.