1999 GMC Other

Air Conditioning problem
1999 Other GMC Models V8 Four Wheel Drive Automatic 150, 00 miles

My trucks belt started squeeling pretty bad thisa week. Spraying WD 40 only helped for a while, and it started again. I am also seeing reduced AC effectivness. Could this be a bad tensioner?
How do I confirm this? Can I replace it myself without a nightmare?
June 20, 2008.

Hi: Yes the tensionier can cause the problem. The belt should be tight enough that you can only move it back and forth about an inch. To replace it shouldn't be too hard. If you need the routing schematic, go to belt routing on this page.