Connect air conditioning a C3/Fiesta/Corsa

Hello everyone. You will see, work for a company that provides us with cars to exercise work, but these cars do not carry connected air conditioning. I say that they do not have it connected because what is standard if it is installed, but the company before leaving them in our possession, disconnects them so that we do not use them, and now in summer we are dying. My question is whether someone could tell me that I have to connect or what I have to do to re -activate the air. The three models we have are from C3, the New Fiesta, and Corsa also new. Thank you very much to everyone.

Thus, to hair !!! Without giving vehicle data, or anything !!
So that the AA does not work in these vehicles, and I suppose they will be new, they can:
- having disconnected the refrigerant pressure sensor.
- Have disconnected the compressor.
- Having emptied the gas circuit.
- I don't think they have removed the feeding relay because but the motor fans would not work.
- The AA button cannot be disconnected because it is integrated into the ventilation control table.

So investigate ....

THANKS RECOKO. It is true that I have little information, but I have been investigating and I think the problem is that the compressor is not connected, because what is in C3, there is like a yellow plug that lacks the connection cable, which on the other hand, is therefore loose. Can that be ?? I have that is located in the C3, but the party and the Corsa still remain. Ah! And they are all the last model. Thanks again.