Nissan Repair: Alt Tensioner pulley, tensioner pulley, time joe

Question
I bought my brother a car and have fixed several issues. the one I am troubled with now is the Alt. AC belt tensioner. The prior owner put a belt on skipping the ac when it broke. I cannot find out how to adjust the tension with out cutting the belt off. When I do that I cannot go back. Now the belt is frayed and wraps around the Alt. Main and tension pulley. The adjusting bolt was almost falling off. When I rebelt this correctly does the tensioner pull back the idler or the Alt.? It is too tight to see under there and I do not want to jimmy rig this a second time.

Answer
Joe,

If you are going to replace the airconditioner compressor pulley just get another factory belt and install it.  I bet the short belt has been leveraged in place by spinning the motor over.  Be sure the compressor pulley is replaced and just get another belt of proper length.  Now, use the idle tensioner to adjust to tension the belt.