Air conditioning failure Seat Ibiza 2007

Hello everyone, I would like you to advise me about a problem that I have with an Ibiza. As soon as the air conditioning compressor appears in the sun, it does not start. I haven't touched it yet but I wondered if it would have something to do with the thermostat that carries in the mirror. And if so, any brief note of how to disassemble it would be a great help, before giving him hand.
Thanks in advance for the attention. And especially for your contributions that are of great help.
greetings