I've got a 93 240 wagon. The car has a new condenser and reciever dryer. When I charged it (134a) it blows cold air at idle , as soon as I raise the rpm's to 3500 or so the compressor will kick out and when it trys to restart.it produces a terrible screach eminating from the compressor clutch. There seems to be no happy medium, either it cycles with too little of a charge, or it produces this scenario if I increase the charge.