Should the fuel reset switch on a 1998 ford explorer be up or down?

There's no "fuel reset switch" in the common understanding of the term on a 1998 Ford Explorer. There's no switch that resets the fuel system in the way that, for example, a fuel pump reset switch might exist on some other vehicles.

If you're encountering a fuel-related problem, it's likely something else entirely, such as a faulty fuel pump, clogged fuel filter, or issue with the fuel injectors. You'll need to consult your owner's manual or a qualified mechanic to diagnose the problem.