I just bought a used '99 Beetle that needed charged.  I took it to my
mechanic on Thursday and he charged the a/c for me and the air worked
perfectly for about a day and a half--  now with the a/c on it still
blows cold air, but there is a groaning sound and the a/c clutch kicks
on and off repeatedly.

I've googled this, but have not found any similar issues on the net.
Any help will be greatly appreciated.

Thanks, Steve