Thermocouple is the bare copper wire (tube) with the big end (about pencil thickness) and is a thermometer for the AC to measure incoming air. Just to clarify if any readers wonder.
If you have issues and want to fix, then really try the suggestions. There will be no real answer, that was kidding, all answers are possible to be your issue or not. If you do not try to solve, then it wont fix itself.
Even professional auto mechanics try suggestions. They start with the easy thing, charge you, then move on to more and more complex and expensive things to see if it will work, all the while charging you for their attempts. If you can do it yourself for free then saves money. Process of elimination. You have to try the fixes known to cause issues.