My A/C was blowing warm so I took it in and had it checked. I thought it just needed freon since it worked last year. They added freon and still blowing warm. I was told I needed the expansion valve and receiver dryer replaced. I had this done yesterday and then I was icy cold - colder than it's ever been since I have owned the car. Today, is just like before I took it in - blowing warm air. What happened overnight that my A/C isn't working anymore? THANKS in advance!

I opened the hood this morning and saw a blue wire near the battery cable just hanging out. Might the wire in question be the cause of my problem? (see pic).