so you have checked fuse 15 passengers fuse box and checked that you have a feed from the ignition switch on this fuse white cable and a feed on the white/green from fuse
My 2003 Defender 110 TD5 decided to lose all dials and dipped headlights. Speedo, fuel gauge and temperature gauge all register 0 and the dipped headlights don't work.
I have checked all fuses and none are blown, no loose wires on the fuse box...