[papajam]

Welcome to the BB!
Pretty rare car you have there; a GTV with an electric sunroof. Of the very few examples I've seen, they were all manual. To my knowledge, which has been wrong before, is that Alfa did not install sunrooves at the factory but rather they were installed either at port of entry, the dealer or aftermarket. If that's the case, then I'd think that info on parts, repairs and how it's wired would be harder to come by than the car itself.
It sounds though that the electrical side of the system is working if the motor clicks. Where is the motor anyway? Can you post some pics?