1990 gtm400 fuel pump runs without ignition on, battery drains

[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

 

 

Edited September 22, 2020 by Dam Ham
Forgot the relay part

[djjdave1]

Do you still have the old oil pressure sender try swapping the old one out see if your problem is the same you may have a bad oil sender Dave

[KINGENGINEMAINTENANCE]

Agree with last post, very strange condition though. I have had a couple times where brand new parts from the store are defective!!