2000 Grand Am SE Electrical weirdness

When I start the car, sometimes the gauges and windows dont work for maybe 5 secs. Like power isn't getting to them right away. Its even gone for 10seconds without working. Then the other day I rolled the window down and the power cut off for a second then came back on. Has this happened to anyone else? Also my brakes make a funny humming sound when im stopped on a hill. Like they aren't totally holding if I dont push all the way down. While im stopped I hear this strange light popping/clicking from the brakeline. I can feel the popping through the brake pedal. Can anyone assist me?