I don't know why but my brake light would sometimes goes on/off and flashes. Often when I accelerate, the brake light comes on, and then goes off. Sometimes it would stay on for a few seconds, then goes off. Also, I'm not sure if this is related, but with the A/C on, when I accelerate, I would get this whining sound. When the A/C is off, there's no whine. I'm starting to think it's the alternator. Am I right?

 

could be your brake fluid level just at the edge of tripping the low fluid level contact switch. Check that one out.