2003 Chevy Tahoe New Tensioner?

I have an 03 chevy tahoe and it was making a ratcheting sound from under the hood when it got to a higher rpm with the ac on. I turn it off there is no sound. I had a mechanic look at it and he said that it has a serpentine belt that runs everything and a separate belt that only runs the ac. On this ac belt, it has a tensioner that mounts to the ac. When the rpms get up, he says that the tensioner is shaking because it has a weak spring, needs new tensioner. An ac tech, said the 2000, 2001, 2002 Tahoes were doing this and they started replacing the tensioners, only to find out that it did not stop the noise. Later they come to find out it is the clutch trying to lock up in the compressor, faulty compressor. I have replaced the compressor & serpentine belt & the squealing continues when I accelerate. Have you heard of this, does it make sense, do I have other options? Does it need a new tensioner?