2012 fusion a/c problem

This is strange. Mywife's fusion had heater and a/c work fine last year. tried a/c for first time this season and no cold air. Checked pipes under hood, they are ice cold, compressor is working but only heat poors into cabin. At the sugestion of a YouTube video, I tried turning all lights on, including fogs, a/c works fine. Next startup, you have to do same process. My wife says that today she tried turning on lights, got a/c, then turned off light and drove the rest of ride home, and a/c worked fine. Any one have any ideas? A/c pressure is fine as well. If more info needed please let me know.

i had this same problem and had to replace the sensor in side the dash,its in the middle but the dash has to be unbolted and pulled back to get it,center console has to come out as well its a job but can be done