What we want to do is get the door panel off again to access the inside. I would strongly recommend removing the door glass as well since the access behind the door panel is tight with it in (it is just two 10mm bolts, then lower the regulator and lift the glass up, rear end first).
With the door off, first do a visual inspection of the key detection switch. It is mounted to the back side of the lock cylinder if it has not fallen off. If it has fallen off, you need a new switch (they just have thin plastic clips holding them on that break off).
If the switch is intact, carefully pry it off the lock cylinder being careful not to break the plastic clips holding it on. Looking at the inside of it you will see a raised rib that engages the lock cylinder, gently turn it either direction twice each way and see if the locks cycle.
If they cycle both directions, then the wiring is good in the door and likely the switch is just failed (doesn't turn far enough to engage when using the key operation).
If the locks do not cycle both directions, unplug the switch. Looking at the three wire harness you have a black wire and two "other" colored wires.... usually a red/green and a green/black, but 2004 had a few oddballs. Never the less, with the connector unplugged, short between the black wire and one of the other two wires twice and see if the locks cycle, then between the black and the other wire twice and see if the locks cycle.
If the locks cycle normally this way, then the switch is bad.
If the locks still do not cycle in either or both directions, then the wiring in the door is your most likely suspect. To address this you will need to remove the door speaker, then unplug the door harness connector in the foot well and pass the entire harness/grommets through the chassis and into the door, then pull the connector out through the speaker hole. You can then trim down the rubber grommet to inspect the wiring for fractures inside the grommet.