Hi to all. I have a 1991 940 with A/C retrofited to R134a. Is it normal that the compressor continuously engages-disengages when running, with a duty of 20-30 seconds ON and 5-10 seconds OFF? The A/C systma has only the low pressure switch on receiver and a high pressure security valve on bottom pipe. Perhaps it requires more gas? it would have charged about 1 Kg (35.27392 oz, 2.20462 lb)
many thanks.