I Have a 91 Deville, converted to R134, and the AC was working fine. Now, it suddenly acts like it is plugged or icing up. The pressures on high and low start out fine and it cools well for 5 minutes, then the compresser starts short-cycling and the low pressure drops and the high climbs into the 350 range. I have replaced the high side temperature switch, tested the low side switch, and tested the low pressure cutout switch. I have removed the lines and checked for blockages. The one thing I have been unable to check is the orfice tube- Does any one know where it may be located? I have called the Dealer, and they had several suggestions, but it was not there. Could it be built into the dryer? Any other ideas on what may be causing the problem?
Thanks!