Take the dead fuse and hook up a 12 volt lamp to it.
Pug this into the place where that fuse is supposed to go.
If there is a short somewhere or a heavy load the lamp will light and limit
thecurrent in that circuit so no damage is done.
Now you can disconnect each of the items  one at a time that this fuse is
protecting.
When you disconnect the problem, the lamp will go out and will have isolated
the problem.
This also lets you flex and maipulate wires and cables to see if they are at
fault.
Realize that with this test lamp in place other items on the circuit will
not likely work well as they can't get full voltage.

Charlie