I just got a used
You could have a leak in the AC system ... if you just bought the car, the previous owner might have filled the Fre-on just before selling it to you, which would have hidden the problem. If this is the case, take it to a mechanic and they can probably find the problem.
Your compressor might not be compressing properly -- when you put the air on full-cold do you hear the compressor kick on? If not, it might be a bad compressor, or no coolant. Once again, this would require a mechanic to give you all the details
Your AC system might be in perfect shape, but out of coolant anyways. A mechanic should be able to fill it up for you in short order.
Unfortunately, if you are not experienced with working on cars, the AC system is not the safest to be working on on your own. It is highly pressurized when filled with coolant (which is a toxic substance) and without the right tools and experience, you could get severely hurt by loosening the wrong bolt at the wrong time. I highly recommend taking the car to a professional to reduce the risk to yourself.
on May 26, 2011