Battery in Trunk wiring completed, now no power at all

Put the meter on continuity check.....measure from chassis to neg side of battery.....it should beep. Like others said, sounds like a ground issue. Or that main power run to the Ford solenoid.

The meter will save you allot of guess work ;-)
put your meter on the batt positive post & a nearby good ground & that'll elim or confirm the ground side as a culprit in 10 seconds. if good, go to the hot side of the furd solenoid & it should be hot & work downstream on that power side till you find the open