Why would a owner wire a fuel pump directly to the battery?
because something must be wrong with the circuit. that is a bad situation, you should find out what is wrong with the circuit and repair it. for one thing, in the event of an accident the fuel pump could keep pumping fuel. possible explosion/fire hazard.
If this is a dual tank truck the tank selector switch on the dash is probably bad. They were troublesome. HTH. -Jim
Search Ford F-150 Questions
Ford F-150 Experts