Windstar 3.8 serpentine belt is tensioned by a belt tensioner. This is a pulley about 4" in diameter toward the back of the engine with a built in spring that pivots the pulley toward the back of the engine keeping the belt tight. there is no adjustment. Put a long rod into the gap just to the right of the pulley and rotate the pulley upwards by pushing down. You will be pushing against the spring. This also allows removal of the belt.
Replace or tighten the A/C belt. If equipped with a serpentine belt, replace it.
No your timing belt/chain is different from your serpentine belt. Just make sure the groves on the belt match the groves on the pullies. Other wise you will have premature belt failure.
belt rotachion
There should be a diagram of the belt's routing somewhere under the hood. There is on my Aurora.
the only belt with a tensioner is the timing belt, to tighten the alt belt loosen the adjustment bolt then tap the alt back then retighten the bolt
One belt in two configurations. One for cars with AC and one for cars without.
If you're certain that the sound is from the serpentine belt you should check the belt tensioner. A weak tensioner spring will result in slipping and a noisy belt.
i have a 96 windstar, 3800cc, maybe about the same, take a long prybar to the slot on top of back component, maybe power steering pump on yours, it will be on a tension spring, push down. this should give enough slack to get the belt on or off, if not loosen the altenater bolts just enough to give another quarter inch.
A shop manual.
loosen the pulley, side the belt off, slide the new one on, tighten the pulley
96 grand Cherokee doesnt have a fan belt, its a serpentine belt. And if you look down to the right of the fan there is a pully which acts as the tensioner, youll use a socket to loosen it up and then youll be able to slide the old belt off. Keep the box from the new belt so you can see how the new belt loops around each pulley. Be sure to tighten the belt pretty tight so it has minimal play or youll get some sqeaking whenever you run your AC.
It's on the radiator shroud or brace, on the right of the fan.