Dam Ham

Before replacing oil sending unit all was fine. Day I replaced it a huge parasitic drain on the battery occured. Following the noise I discovered the fuel pump buzzing away, even without the key on. Only way to stop it besides disconnecting battery is to pull the fuel pump fuse. Thats even with the relay completely disconnected . only pulling fuse stops it. Ive been trying to check the wires with multimeter for shorts, but one major problem is every schematic, including the official 1990 GM shop Electrical and Wiring Diagram Manual I own and all the book and download schematics show fuel pump related wiring as Grn-Wht, Blk-Wht, Red, Orn, Gry, Pnk-Blk, Tan-Wht. Mine has Purple wires ? None show purple. I suspect purple is what they show as Grn-Wht. Anyway. The run on fuel pump is baffling me