No power through the car

Hello, since you cant communicate with the scan tool, you should check and see if you have power at the Data Link Connector. Pin 16 is battery power and pin 4 is chassis ground, pin 5 is ecm/sensor ground. Thats where I would start. Does this have the white colored Data Link Connector? I believe thats the one that is kind of hard to tell which way the connector is facing. But with your multimeter see if pin 16 has power, it probably doesnt. If not we'll go from there and try to trace back the issue. It sounds like you missing a main power feed somewhere from one of the Junction boxes. If power is missing check the OBD Fuse 7.5amp under the passenger side dash.

There may be corrosion under the bottom of the fuse block in the engine compartment, You want to just start checking the under sides of each fuse panel for corrosion. With a power lose for all interior lighting, that would be my first suspect. Also check for any water intrusion, wet carpets, anything like that as well.

https://www.2carpros.com/articles/how-to-use-a-voltmeter