Here is a detailed flow chart and vehicle specific wiring diagram upon request how to diagnose electrical issue with ac compressor automotive news ask a mechanic forum launched! how to diagnose electrical issue with ac compressor by jared goss - may 21, 2017 0 8042. Automotive air con wiring diagram. At this stage in the air conditioning circuit and cycle diagram, high pressure liquid refrigerant will flow down the liquid line, through a filter drier that is designed to prevent contaminants from flowing through the system, and on to the metering device.