Chevrolet Repair: 1994 Chevy 3500 fuel pump never shuts off, chevy 3500, fuel pump

Question
I have a 94 chevy 3500 with a 7.4 the fuel pump never shuts off unless you pull the fuse.  even if you pull the relay out it still runs

Answer
you have a short.  If not a problem with wiring under the truck, look for a place where current can enter this system.  It is possible the ign switch is bad, but pulling the relay should stop the pump if this is the problem.  

Without seeing the truck, this is a tough one.  It is a short though.  Any recent work done?  Screws put in?  look for a place where the wiring is rubbing the frame and wore off the insulation.