Why did my brakes completely stop working then the next day work again. 97 grand am?

Intermittent brake issues in your 1997 Grand Am could be due to several factors, such as air in the brake lines, a failing master cylinder, or a malfunctioning brake booster. If moisture accumulated in the brake fluid or if the brake pads were temporarily stuck due to rust, that might explain why the brakes failed one day and worked the next. It's also possible a loose connection or a failing sensor reset itself overnight. To ensure safety, it's advisable to have your braking system inspected by a professional.