I have a 1994 chevy silverado. I replaced the entire AC system (condenser, compressor, accumulator, hoses and sensors) a couple weeks ago. Everything has been working smoothly but now as of last night the compressor doesn't cycle the clutch stays engaged. It does disengage when I turn the ac off but it doesn't cycle while the ac is on. My understanding is that is should cycle? What is my issue? Any help would be appreciated. Thanks.

 

First, a couple of questions. What refrigerant is being used, and second, what are the high and low side pressures when the AC is on max (and the engine is running)? Also, how long did you pull a vacuum for, and how long did it hold vacuum after shutting off the vacuum pump?