On my old Zetec, which may be different, it was directly below where the coil pack is on the Duratec. It's in a box and has a wire from one side to the alternator, other to the battery.
But if you're reading 14.4V at the battery, the Mega Fuse is good. You would read the battery's voltage only if it was bad, since it's in-line with the alternator/battery.
