I have a 96 two door blazer, i seem to be having problems with my belt. When the ac is on the belt starts flapping away,when i turn the ac off it runs normal. The belt is new as well. I hope someone could shed some light on this issue for me.

 

What is the condition of the tensioner? It is moving back and forth? It might need to be replaced.

 

I know the little arrow it has on there isn't lined up with the other one. That might be the thing causing the problem. Don't thos need to be adjusted just right?

 

Theres a tensioner spring that will get worn over time. I dont think theres a way to adjust it tho...

 

I will replace it this weekend, i just haven't turn my a.c. on, i don't want the belt slipping off with it running. The one that is on there has a arrow on it and isn't lined up with the other line. Hopefully it fixes my problem. Thanks for all the help

 

I've attached pictures from my 1999 GM Service manual that discuss how to tell if the tensioner spring is not working properly or not. It is likely similar for yours. Good Luck!

 

Thanks Christine. My index mark is on the edge of the indention. I think that is causing the whining.

Edit: Nope, the whining was the idler pulley. Fixed!