human
I'm having trouble with my car's air conditioning system. What's the cause?
assistant
The most common cause of an air conditioning system not working is a lack of refrigerant. You can check to see if your system has enough refrigerant by looking at the pressure gauge and making sure it reads between 10-20 PSI (pounds per square inch). If it's lower than that, you may need to add more refrigerant. Additionally, make sure your condenser fan is turning and that the compressor is running. Lastly, check to make sure all hoses are connected properly.