Quote Originally Posted by BB767 View Post
The horn and fan wiring have a lot in common; the CB’s are next to each other, as are the relays. They are both powered by the direct battery bus which should not be associated with the ignition switch. The wires for both circuits run through the front harness. I would start by checking this area in the fuse panel for contamination (metal shavings) or loose or shorted wires. As for the ignition switch, what stay’s on that shouldn’t? Lights (stop, tail, turn, high, low), fuel pump, heater, gauges (any or all)? Check each item individually for clues to what is shorted.

Unfortunately the wiring is the one area in my car I completely left to someone else (during the initial build). Should I just change the fuse box (and all the fuses) as well as the ignition switch? And check for any water leak issue?
For the ignition switch, all my gauge lights stay on, as well as the fan.
turning and removing the key had no effect.