I have a recently purchased 04 2500 hd with duramax, has run fine and last night started and backed up and died like key was turned off,will crank but no fire. I changed and primed filter and no help, then found a blown fues under hood, the 25a under the fpump fuse, it is not identified in the oweners manuel, thes just call it #1, I have changed it and blows as soon as I crank? Any help will be greatly appericated.Thanks