So the interior lights and central locks work except the hatch in the back doesn't respond to central locks, you can use a key to lock and unlock it though and the cargo area lights 3 total don't turn on. I tested the bulbs and they work on my bench power supply, I tested the voltage going into the bulb harness and it came up 0 volts. I'm hoping theres a solution other than trying to find broken wires.

 

you can grab the wiring diagram from volvowiringdiagrams.com and also find some online info for which fuses, relays etc (and if the CEM is in play). The wiring diagram will show you junctions to test from but the simple start is fuses/relays then the local connector in the hatch. Keep in mind hatches take a lot of physical abuse - slammed closed etc so I'd pay close attention to broken connectors/bad sockets or a bad actuator in the hatch area.