today after driving my car i turned it off for about 30mins. and when i cranked it up again the ac was on and there was this rattling noise. so i popped my hood and it sounded like a belt was rattling or one of the pulley's. as soon as i got in my car i pressed the gas and the noise increased. then i turned off the ac and it cut right off. is this just a loose ac belt? what should i do?thanks in advance for any replies