2002 Ford Windstar Serpintine fan belt

I dont know specifically about your car but ill give her a go!

First under the hood look around for diagrams for belt routing, it should tell you if there is a tensioner and what way to turn it.

If there is no tensioner then you will have to loosen the alternator, put on the belt and then tighten the belt up by moving the alternator and bolting it down.

Ford created another winning design with your engine by putting the tensioner on the backside of your engine down towards the bottom. There is no bolt to loosen. There are one of three ways to move the tensioner. #1 You can fit a breaker bar on it. A ratchet wont work because the heads on them are usually too thick. #2 You can purchase a belt tensioner tool from your local auto parts store. It's a thin peice of metal that will reach back to the tensioner. #3 This is what I learned to do at the dealership: route the belt onto every pully except the top pulley, grab the belt and pull real hard until the belt fits around the last pulley. Watch your fingers, though, the belt may tend to roll the pulleys. I learned to use this last method quite a bit. It was better than loosing your cool over not being able to reach the tensioner.