it's hard to tell which one is squealing but I will have belts today. Will change out and report back.

geo, I followed your advise and hit the pulleys with some 220 grit, then I wiped down everything with a clean cloth and installed the three new belts. Started her up and she runs beautifully. no sounds, squeals, whines, nada. I tightened the tensioners and the ps pump to give the 2 vbelts about a 1/4 inch play. Hope that's within spec. Another problem solved. Now it looks like my next monty adventure will be the front brakes, as they are starting their own little noise as of late........

Spoke too soon, the belts were quiet for about four days and now the squeal is louder than before. I don't know where its originating from. I drove to work today and it squealed the whole way, when I got home I felt around and their are two tensioners (this is a Gen 1 v6), the one closer to the top and adjacent to the alternator wiggles ever so slightly when I attempt to move it (eng off). The other one (above PS) doesn't move at all when I attempt to wiggle it. So I tightened up the center bolt on the tensioner, as well as tightening the bolt that sticks out to the right at an angle just above it (1:00). The belt seems tighter by doing that, but when I started it back up she still squeals with the rising rpms. I don't know what this is. The engine runs fine, smooth, in temp otherwise. Please help.... !! And if you hadn't read thru this whole post I just replaced all three belts last week...

Drive at a constant speed, then turn on the lights and heater fan full speed. Does the squeal get louder? No change? Belts loosen up after running for a little while due to initial stretch. The serpentine idler belt has one tensioner. You have to loosen the center nut to adjust it, then adjust it with the side bolt to proper tension, then tighten the center nut to lock it in place.

I will go for a cruise right now. Are their "bearings" in the tensioner that would be making that screech ? Currently I have both center nut and adjust nut (1:00) pretty tight. Lemme go for a drive and see (hear) any change.
FYI, whats the lower tensioner called then ? the one above the PS ?

Yes, there are bearings. Sometimes they are replaceable but often not.

The lower one is just an idler that forces the belt to wrap around the device pulleys.

Went for a drive, couldn't tell difference on volume of screech/squeal while heater on and lights on. It seems to lessen as I drive more. How can I tell if the bearings are replaceable or not, or do you have one lying around there in Gerber ? If that's indeed the potential problem ? Or I can take this one off and lube 'er up ?

It's an easy replacement. We found a Goodyear pulley that fits with the addition of 3-5 flat washers between the pulley and the bracket. If I remember correctly, the part number is 49075, but research it. We posted it on here before, so you should be able to find it with a search.

Fasteddy, as I was lurking, I found a tensioner pulley via Napa...ATM 1553401 by GMB ? It's $40. I now will research the part number you gave me. The one from Napa looks like the right one, but as Cheesegrater mentioned, the lower one is just a guide, but to me they do look pretty identical, whats the difference and how do I know if I am looking at the lower one or the actual pulley tensioner ? And last but not least, is this the potential problem from all I have written ?