hi guys i was trying to replace my serpentine belts on my 2004 nissan 350z and i cant find my tenionter? so i removed to pulleys that i THINk are my tentioner pulley because the belts kinda laid on them and they dont have any threads. and now i cant get the belt back on? and suggestions? or opinion?

 

this might help. the two lower idler pulleys are mounted on plates that slide up and down. there are bolts (B&D) under the car that adjust them to tighten and loosen. Each idler has to have the nut (A&C) loosened first because it serves as a clamp to keep the whole thing from moving.