Galaxy AC Issues

Likely causes for those symptoms on that vehicle year include compressor failure or, potentially, a malfunctioning HVAC control module. Do you have access to a scan tool to pull the specific DTCs (Diagnostic Trouble Codes)? Knowing those codes would significantly narrow down the possibilities. Is the compressor clutch engaging?

I don't have a scan tool unfortunately. How can I check if the compressor clutch is engaging without one?

Without a scan tool to command the clutch, visual inspection is next. Pop the hood, locate the AC compressor, and have someone switch the AC on while you observe the compressor's front pulley. You're looking for the clutch plate (the center part of the pulley) to engage, meaning it starts spinning along with the pulley. If it doesn't, and given your symptoms, coupled with potential internal diagnostic faults, the compressor may be faulty. Also, a defective AC control unit could produce those symptoms. I advise having a qualified technician diagnose the system.

Thanks for the detailed info. Took it to a workshop and they confirmed it was indeed the AC control unit defective, leading to refrigerant compressor failure. Repair cost me 980€. Appreciate your help!