That little box in the DC power line to the fuel pump is an electrical filter to reduce any radio frequency interference generated by the fuel pump. It is failure prone, as you have found out. The most common failure mode is for a capacitor inside the box to short out and ground the DC power line to the fuel pump. The most common cause is a spike on the DC power caused by, for instance, a loose connection to the battery or manually removing the battery cable while running.
It's practically impossible to repair since the box is soldered shut and all the internal components are embedded in hard potting compound. I don't know if a replacement filter box is available from Facet (the manufacturer) or elsewhere.
The only practical solution is to cut the wires on either side of the box and rejoin the wires, eliminating the box from the circuit. That will at least make the fuel pump work again. I haven't heard that anyone has had problems with whatever radio frequency interference may be unleashed by this solution.
Hope this helps,
Richard
P.S. Another solution, of course, is to replace the entire fuel pump and filter box assembly. They are available from Facet fuel pump distributors for about $200, and sometimes (rarely) less on that auction site.
