belt tensioner
 

I am a newer member. I wanted to know if it was normal on a 99 blazer to have the belt tensioner move just by pulling on it with your hand. I can get it to move a little (not much) and when the truck is running it seems that it is constantly moving around going up and down. If any one can help I would appriciate any responses. If it is bad is there a thread that shows or explains how to replace it thanks again

i dont think you should be able to move it with just your hands. it is not to bad to change...just a snug place to work on it.

Yeah as cheap and easy as they are to replace I would just change it. Its also a good time to go ahead and put a new serp belt on as well just another cheap piece of mind in my book. I swapped both of mine right after I bought my truck. I keep the old belt in the back with the jack just in case! I would recommend a Goodyear gator back belt as well I think I paid $18 for mine on Amazon.

+1
Def keep the old belt as a spare..cant hurt and for the space it takes up its great ins.