I have a truck with an extended CAB long.

Hi, I have a 2002 gmc sierra extended cab long bed with the 5.3 vortec motor in it. I just recently noticed that the steering was super hardto steer at rest but was fine when driving. I took it home and checked under the hood. The fluid for power steering was all the way up on the plastic plug but had space in the resevoir. The belt was fine and is still in good shapewith no rips or anything. I leet it sit and cool off for about an hour and a half. I started it up and took a drive, it was fine for a while then when trying to pull in the drive way got super hard again, I parked it and noticed at idle the power steering wouldnt work but if I revved the truck up it would work fine. Please help, there is the rest

It moves a little but there is olenty of tension, it almost sounds as if the belt is rubbing at some point though

I found out what was wrong, turns out the serpentine belt tensioner was out. Quick $130 to get it fixed. Thankyou for your help!

Its now doing the same thing not 4 hours after being "fixed" the place is now closed. Now what could it be, could the belt be bad and isnt gripping the pully? Is the power steering pulley bad? I checked the oil again and after trying to steer it smells almost burnt?