What does the fuse block look like? Anything plugged into the ignition-hot or battery-hot terminals? If so, are you sure what they are for? If not, looks like PO spliced into the ignition hot line coming from the ignition switch for the instrument panel circuit instead of the hot line coming from the headlight switch. Should be pretty straightforward to trace them, but maybe not if things are a real mess. Maybe post a pic of what you've found so far as well as one of the fuse block (if not stock)?