I've replaced the female connector, the sockets, the bulbs and still nothing. Ran the ground strap to a different part of the truck, nothing. Considering doing an LED lit license plate or changing the sockets to accustom LED lights... would any of this work?

 

I would check to make sure you have power to your socket , the licence plate lights (atleast in my experience) tend to get corroded and may require alittle bit of rewiring.
but also if you test it test not just the connecter but the wires to make sure its not bad wires and not a bad connector or its a bad connector and the wires are fine.