Welcome to 2CarPros.
First, is the noise from the AC compressor under the hood or is it coming from under the dash?
If it is from under the hood and is a rapid clicking, chances are you are low on Freon. Here are a couple links that will help you check and recharge the system:
If the noise is from the dash area of the vehicle (inside), and is related to fan speed, the fan motor may be going bad.
Here is a link that shows in general how the fan motor is replaced:
If the fan speed doesn't change the sound, then I suspect there is an issue with either a blend air door actuator or mode door actuator. These actuators are responsible for directing air flow and temperature. Does the sound get worse when you change temperature or air flow direction?
Here is a link that shows in general how a blend door actuator is replaced. The mode door actuator is similar.
Now that I've probably given you a headache, let me know if any of these descriptions mirror what you are experiencing. Also, if you could record the noise and upload it, that would make things much easier for me to diagnose.
Let me know your thoughts.
Tuesday, May 28th, 2019 AT 6:20 PM