When I start my AC, it squeals like crazy for the first couple minutes and then subsides. If i turn it on in a high gear on the highway(40+ MPH), it does not squeal, but at idle or low speeds its insufferably loud. Anyone else have the same issue? Im thinking the belt is either bad or loose. I heard it needs to be super tight. I got the Jeep back in January and have not addressed the belt or pulleys yet. It runs ice cold and is amazing when it gets going, but it takes so long to stop squealing.

This also happens with my defroster. I tried WD 40 lithium grease as it was recommended to me once but it did nothing.

 

This happens a lot to various vehicles. Your serpentine belt is either loose or worn. Tighten it up and see what happens

 

never put oil or grease on the belt. get a new belt, prior to install, clean the pulleys of oil and grease. tighten to specification. while belt is removed, test spin the pulleys checking for noise, and wobble. if pulley is suspect, replace it. I have found idler pulleys may leave one stranded when failed.