Check PATS
PATS equals the theft system. The terms are interchangable.
If you are measuring 10.5 volts at the pump itself AND the pump is not running, then the pump is bad.
However, I tend to question the results of this test. On the 1999-2004, the PCM/FPRM does not power the pump to run for very long with the engine off. So unless you performed the test while cycling the key, it is doubtful that you are actually measuring power to pump.
However, if the theft light is flashing, that usually indicates the PATS system has been tripped or a PATS related problem.
Suggest that you double check your work. Esp since you already have installed a new fuel pump. IMO, it is important to determine if the PATS system has been tripped or this is just a bad fuel pump.
Exactly what is the theft light doing?
>>>From Ford service CD
PATS uses a visual theft indicator. This indicator will prove out for three seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS problem, this indicator will either flash rapidly or glow steadily (for more than three seconds) when the ignition switch is turned to RUN or START. PATS also "blips" the theft indicator every two seconds at ignition OFF to act as a visual theft deterrent.