Cold..Hot...Cold...Hot

[ScottyC190E]

Hey guys,
I'm having a problem with my 86 190E. The freon is full and the AC is cold but after driving a while with it on the compressor stops turning on and the air gets hot. Then to get it cold again I have to re start the car. As soon as I restart it the air is cold again and the compressor works untill its goes out again ect... It seems to be on for about 5-6 seconds, then goes off for about 4 sec, then comes on again and the comp. seems to be working to hard. Is this true? In other cars I feel the comp. turn on like maybe once a minute. Can anyone tell me what's up? It doesn't seem to be the compressor or the freon, but the blowers bearings are wearing, and I can't turn the blower past the second setting without it making noises coming from inside the vents but that doesn't seem to be the problem either. Any help is highly appreciated! Scott