Though Luthier's advice is sound and likely that work is needed, I think you have one or more bad grounds. Basically, your instrument lighting is using an "alternative path to ground".

Also, the passenger taillight is on the same circuit (from fuzzy memory) of the center console ashtray light that cause many, many 240 owner issues. Those wires get pinched and blow that fuse often and the logic of them being on the same fuse (if I am remembering correctly) is something only the original designer could explain.