Truck Repair: fuel pump on a 94 3/4 ton, semi trucks, diesel engines

Question
My husbands truck when you shut the truck off the fuel pump will run continuosly until you pull the fuse out. what can he do to fix the problem.

Answer
This is a little out or my area i deal with semi trucks. Don't know alot about pickup trucks. But to take a stab at it diesel engines normally have a shutoff solenoid down on the fuel pump.  That has probably gone bad and would be the first place i would start. Now with a pickup i don't know where its located would check there first. with a semi it would have only one wire going to it. To check it you can disconnect that wire and set a volt meter to ohms and put one lead on the stud you unhooked the wire from and one lead on the mounting screw of the solenoid and if it read ol then its no good.