AC issue... Compressor on its own schedule.

[stevesparts]

Did you add any r134 to it?? sounds like to much 134 in it, overfilling will do what you are saying. and freeze up then blow hot air then cold,hot,ect,ect. sounds like you need to bleed off some r134. I did it one time and just had overfilled it as i thought just a little more would be better. but it wasn't. so check that out.
plus Wiseman tip about the dryer filter is a good one too :)