Central junction box / fuse box

Our back running lights and taillights
stopped working suddenly. We were told to
check the wiring so we had that done. The
wiring was said to be fine. So we were told
the next step would be the fuse box in the
passenger cab. I would like to get the fuse
box in my vehicle tested to see if it is
working properly but I haven't heard of a way
to do that. So we are going to replace it
hoping that that would solve the issue but
we are trying to locate a fuse box and are
having difficulties. So we were told that
there are some fuse boxes that are
compatible with our fuse box even though
they are from a different make and model of
a car.  I would like to  know what car that
has a fuse box that is compatible with the
part that we're looking for?