Windows, gas gauge, ac, and miles till empty

You need to get a working schematic and trace the power supply. They use something called a fusible link which the wire in the insulation will melt if the load gets to high. It's a piece of wire that's a fuse and the only way to find it is to find it location and test it with a test light or a voltmeter. It could also have a different fuse. I guarantee that a Cadillac has at least 2 fuse boxes. You need to check the schematics and find was has interrupted the power supply. Unless you have a lot electrical experience I would take it to a EXPERIENCE MECHANIC Cadillacs have A LOT of wiring and and it will be difficult to find the issue. But first check that all of the fuseboc/ fuse boxes have been found and manually check each fuse with a test light or voltmeter.