Does anyone kow if I put in a new a/c compressor do I have to charge the system right away or can I leave the wires disconected so that it does not ingage untill I get it charged. Or should I put oil in it and hook up the lines. then charge it not sure if the old system had a leek there was not much R-12 left in it at all. My old a/c compressor was not seezed up but had bad bearings on the pulley.