Great idea. Why did I not think of that? Thank you!Cobble a 15 Amp fuse into your power wire to the pigtail on the firewall. If the fuse blows, the pump is shot. If the fuse does not blow, you can go to the rear of the truck and listen for it running. The idea of the fuse is to protect the truck's wiring if the pump is drawing more than the wiring can support safely while you go to the rear, listen, etc.
EDIT/ADD: Take the battery to the rear of the truck. There is a 2-cavity connector ahead of the license plate. One gray, one purple wire.
Disconnect it and apply +12V to the gray wire, ground to the frame. Now you're at the rear of the truck, and if the pump runs, you should hear it. Plus if any wiring burns up, it will only be the in-tank pigtail or the sender pigtail, both of which are easily replaced.
Happy New Year