i just have a quick question about my 93 vigors a/c system..well about 8 months ago i bought the vigor and had a mechanic switch the engine with one from another vigor..when he did this, he completely emptied the a/c system of all refrigrant..the a/c worked before the engine swap was done... but now i just pushed the a/c button to see if the compressor would turn on but nothing..is it possible that it could be because of the system being empty???thanks for any help..