Chevy Equinox electrical?

My 2005 Chevrolet Equinox used to turn off radio when exiting my vehicle, and my interior lights would turn on entering, and my driver window did work. But recently I noticed none of these work, they very, very rarely do, and I don't have any issues with any other door/window, they all work just fine. The sensor, or whatever it's called, to know when the door is closed or opened isn't bad, I don't think because it's interfering with my windows too. I'm not quite sure where to start on troubleshooting it.