90 Mustang fuse box | Ford Forums Jan 31, 2006> AND the cover from his fuse box. Does anyone have a diagram of a fuse > box layout for a 90 Mustang LX 5.0 they could email me? Or can someone > tell me which slot the horn fuse is in. I want to start with the fuses > and work my way towards the horns to see where the problem is. Dave covered it well, but here's a diagram in case you're more of a Fuse Box Diagram > Ford Mustang (2015-2019.) To remove the trim panel, lift it from the rear retaining hooks, while pulling it toward you and swinging it away from the side. To reinstall it, line up the tabs with the grooves on the panel, drop the panel back into place, and then push it shut. To reach the fuse panel, first remove the key code card.