Hello, there are several options, the average switching temperature of air conditioner is +5 degrees, at less than +5 degrees the air conditioner will not turn on. Refrigerant pressure may be below the turn-on threshold. A relay may not work or a fuse may burn out. I had a case when someone changed the cabin filter and disabled the thermostat, which is behind the glove compartment, the air conditioner did not turn on. So I sincerely advise you to contact a specialist in your city. Theoretical and more detailed information you can find here -
https://www.airconservicing.org/. Good luck!
Edited by luke268063 - 15 August 2021 at 12:01am