Alfa 33 heating

[vivian]

Hi all,
Im having a problem with my air con system in my 1.7l boxer. Last winter my mechanic showed me a switch under the bonnet to turn it from cooling to heating, i swapped it back to cooling in summer but now cant find the switch again! My dad has looked as well, we cant find it! Does anyone have any directions as to where it is- I remember it was on the passenger side.
I dont want to ask the mechanic again as I no longer take my car there..

would appreciate the help
vivian