radjaco

Yes, but today I checked again. Waited more than 5 minutes but the hissing sound did not go away. So, I turned it off as I have already described through air conditioner button (on and after off).
Then I tried on a hot engine: every time I start the car it comes on hot or cold and after the AC on and off operation the hissing sound disappears.

jfrahm

Must be something else then. Can you record it?

You might look and see if the AC compressor clutch is spinning (not just the pulley, that always spins) and if cycling the switch is making it stop. Maybe it's making the noise.

The endmost black disk will spin if the compressor is turning:
http://www.autohausaz.com/secure/par...4B0260805B.jpg

radjaco

Ok.Thanks for the help. Seems I have solved the problem; I had my AC set on LO on both sides. So, when I used to start the car the noise like hissing would come on: does not matter the car was hot or cold. Today I tried to set a temperature manually to both sides on +20 and turn off the automatic control. Now the hissing is gone at startup.
As for the AC I do not have it charged yet since I bought it 5 months ago. There are no specialists in this country where I am staying at the moment. One of them told me the compressor problem another talked about the hoses... anyway, I decided to give up the air conditioner charge idea for the time I will learn myself how and from where to do it. Simply to tell them from where to charge and how.
As for the black disk, please specify for me which one as I see that everything is turning but more precise guidance I would appreciate.
Thanks