I recently had my mechanic put on a new serpentine belt and water pump and since then, the serpentine belt has been squealing every time I turn the A/C on. Come to find out, nimrod mechanic didn't check the idler pulley or even bolt it all the way back on. So I had a friend of mine slap on a new idler pulley and put the belt back on and everything was great. The belt was in pretty crappy shape after being driven a couple hundred miles on a worn out and wobbly idler pulley so I asked nimrod mechanic to put a fresh serpentine belt on it. Big mistake. Now it squeals when I start it and when I turn on the A/C. Since it worked fine when my friend fixed it, I'm pretty sure the belt just needs to be tightened. At this point i want to keep the mechanic's hands off my jeep so I'm doing it myself. Unfortunately I've gotten several different answers on whether or not I need to loosen the idler pulley bolt a bit before I tighten the adjustment bolt and really how to tighten it in general (one tutorial even said something about the water pump. Calling BS on that one unless someone tells me different). I was hoping you guys could give me a consensus.