I have two problems with the A/C:

1. When I first start the car, the A/C will click loudly, unless the air vent selector is set at both up and down. Any other selection (e.g. air aimed up or air aimed at footwell) will cause the clicking. However, after the car has been running for a while, I can choose the other settings without the clicking noise.

2. On cold days, the A/C runs fine. But on hot days, it blows warm air and cannot cool the cabin.

I had the A/C checked at two different places. Both confirmed it is filled with freon and there are no leaks.

Any suggestions?

 

So if the second button is selection, as shown in this picture, there is no clicking:



However, if I select the other buttons, there is clicking until the car has run for a bit.

 

Can you tell where the clicking is coming from? Is it the motor on the side of the main air duct box?