It could well be a fuel pump, but it might not be a fuel pump. It could be any number of things. It could the nest of a Mud Dauber. I just don't think it's a fuse. Where to start, I do not know.
This is one of the many the complexities faced by the more recent iterations of
the species I belong to. DC, DCC there's a whole range of them. It's a modern
miracle any of us get out of bed in the morning.