1995 s10 blazer ac compresser

i have a 95 s10 blazer 4.3 v6 motor have put 3 reman. ac compressers and 3 acumulators and 3 orifice filters every time i replace the oil and r134 coolant every time the compressers lock up with in a mile whwn i turn the ac on help me am i not doin something right? i am at witts end !!!