No Power

When you say all power, does the radio work? Interior lights? If no, I would look at the battery and if a cell went bad. If it just won't start (no clicking), try starting it in neutral if it is an automatic. There is a fusible link at the junction box that could burn through in case of a short somewhere. Also a burned terminal where the main feed goes in/out could also cause an issue. Those would also kill all power.