1997 Venture smoking belt? Bad Belt or Alternator?

[Jag1980]

This is my In-laws van I am working on.

I guess it was smoking so bad that they sprayed it with a fire extinguisher.. lol

Within the last 8+ month I have replaced the Belt tensioner and the serpentine belt with a Gatorback Belt.
Month later they had some squeals only when turning the wheel, scary loud!
Someone sprayed something on it and it stopped.

Now here come the problems now and what I see.

I started the car and it was quiet. then it starts to get loud and then louder! I shut the car off before I could see any smoke. The belt seems to have good tension on it.
I was told that the problem could be that the pulley on the alternator is not turning properly causing the belt to go over it faster than it can spin, or something like that?

Could the alternator be the cause of this problem?

(UPDATE)

I just now looked at the belt numbers..
The belt numbers on the installed belt are for a 140amp ALT - 4060705
The ALT on the Van are for a 105ap ALT which is what the car has..4060695
I did not buy this belt, they did and I just installed it..

Now could this wrong belt be the cause of the problem and or could this have messed up the Alternator?

Or did I waste a bunch of time taking this alternator out...

[discnik]

Welcome to the forum !

One thing you could do, if you have the current belts number, is get ahold the parts house and see if there is different number for the 105 amp belt.

I have noticed on a few chevy's that the larger amp alternator will have a slightly larger pulley diameter. If the belt you have is for the 140 amp alternator it could be slightly larger in diameter than a belt for the smaller alternator. So when the belt heats up it could lengthen in diameter causing slippage over the pulleys. Since you have the belt off, removed alternator, check all the pulleys for wobble, (worn bearings), and rough feel, or noisy. Especially the water pump pulley.

Just some thoughts.

[Jag1980]

Thanks

From reading the number on the 2 belts, the one that was installed on the car is 1" bigger. I also did not hear the loud squeal until about 20 or so seconds after the motor was running.

If it was a bad alternator I would hear the squeal right away correct?

I spun the alternator pulley with my hand and it turns ok.
I checked the tensioner also and it feels smooth.

Here's a image of the belt. Does this look like wear marks from slipping?
I'm thinking it does

[discnik]

It would appear your have answered the question and solved your problem !