General Maintenance & Repairs - Air Conditioner is groaning...

So I'm on my first longer trip with the '98 SS today and after about 20 minutes of driving and using the AC on "Max" setting at about half fan power it stopped pushing air period. If I crank it up to full power I can hear the AC groaning as if it is trying to work. If I turn it off for a little while, or even just down to low, it will eventually start pushing out cold air and then once again give up on being able to push air period. Ideas? It's hot, muggy, rainy, and I have to have the top up lol. Thanks in advance

Sorry I can't give anymore detail, in short AC stops pushing air and makes a loud groaning type noise as if it is trying. After a little while on low it will start pushing cold air again only to once again give up pushing air all together. Any ideas?