I know of at least four bikes now that have suffered from either intermittent or complete loss of the 12V power supply. In all three cases the culprit has been the fuse. The fuse appears fine, and may even pass a continuity test. It might also appear that jamming the fuse tighter into the holder solves the problem. However, I've now seen three of the actual fuses fail (not blow but simple mechanical failure) - one of the end caps comes completely off. My guess is that continuity passes because when handling the fuse you put enough pressure on it at the right spot.
So, just go to the hardware store and get some replacement fuses.
There's one fuse holder in the compartment that holds the DC/DC converter and another fuse holder in the space underneath the floor just behind the DC/DC converter compartment (you can reach up from the back of the bike and access that one without removing any panels).
