FWIW, my Trooper had a similar situation where the fuse for the fuel pump would pop randomly, most of the time during start-ups but it could be on the road or wherever. Turned out that I had a bad alternator. I had also been having what I thought was a drained battery (probably was never charged properly). All of my weird electrical problems were probably due to the alternator surging or not charging properly.
I have since replaced it and everything is fine.
Good luck!

Stefan Doerr
'94 Trooper LS
6.5" lift, 33's, G80 and other stuff
http://community.webshots.com/user/smd94trooper