Ok during my lunch brake i went to go get food. I turn my car on and the radio is turning on and off on and off im like ok thats werid. Then i look at my volt meter it is bouncing in the red zone. So i shut off my radio and everything my volts go to 14 then i turn my headlights on and see the volts drop and hear a loud BUZZZ comming from the dash. So i turn it off few minutes later im back at 14 volts. So i park the car make sure all the alternator connections are good. Still the same problem so with the car off i checked the volt guage it said i had 12 so i turned my headlights on and it went to 0 and made a BUZZ turned it off it was kind of in the red. So does this sound like my battary took a crap on me? The alternator is a new alternator the battary is about 6 months old. ITs an optima Redtop. Any ideas. Also the past few days when i have been driving intraffic the volts have gone near the red.

PLEASE HELP!!!!