Check the main fuse. Better yet install a new one. Not that it's blown but the contacts are not good.
Lucas - I think corey is talking about the posts on the attached pic. I've had problems with things coming loose here as well, despite the use of external tooth lock washers. If you pull the panel in the front compartment and expose the fuse box, radiator cap, etc., you will see these three studs. One negative, one positive, and one in the middle - I don't know what that is for. This can be used as power supply for ad ons, like a winch. As Corey stated it has cables, then a nut, then additional wires (if you add something), then a nut, etc. They can loosen up.I’m having this same problem. Anyway you can get a pic of what you’re talking about?