1991 corvette AC control failure

I have a 1991 corvette that has nothing displaying on the AC controller except for ---. Have replaced controller itself but has the same result. Believe it could the temperature sensor unit in the car but have no info or idea where it is located. The AC system is fully charged. I live in Invercargill New Zealand (World's Fastest Indian) so there is no Corvette or even a Chevrolet dealer here I can use. Car was brought out of Ca
Thanks for any input
Kiwi Chris