What would cause a squeakingchirping noise under the hood of a 99 Tahoe Belt belt tensioner and idler pulley have all been replaced Could it be the alternator?
Did you change out the belt? I had a chirping and squeaking on
mine and my 95 Impala and I couldn't isolate it so I went with the
cheapest repair, a new belt and low and behold it solved the
problem. As soon as I hear a noise now, it's belt first then more
expensive parts last! Good Luck