I know it’s old but what was it? I’m having a similar problem with no electricity at all but battery is good and all connections on new. I used a multimeter to check the ground as well and seems good. I’ve been having an intermittent issue of start and no start clicks, I figured battery connections or starter. I ended up replacing the connections and cleaning up the posts and it was starting perfectly for like a week. Now it has no power to anything, with or with out key. Battery is full, connections are tight and new. I don’t know about the white wire that goes to the fuse box being an issue but what other ideas does anyone have?