Unresponsive Signals and Windows

Hey there, me again. 2002 Impreza WRX wagon. So I took my car for a fill up. On the way over, power windows and turn signals worked fine. Filled up my car, got back in, and suddenly no response from either. Not even dashboard lights from signals, and PWs doing nothing. Occasionally the hazards might make noise and might even show dash lights too. I tried checking relevant fuses in cabin and engine bay, they're good. Gonna check relays next. I read that it might be something about the ignition key cylinder, or a wire? Tried wiggling my key and power cycling, still no dice. I wouldn't be surprised if it was some wiring shenanigans because a previous owner swapped the steering and messed with the wiring (need to check under there at some point). My friend had his alternator fail recently so he thought he'd test mine with a meter, says it doesn't seem healthy.

So has anyone else had this happen? Please, any tips, or am I on the right track?