The alternator died first and drained your battery shortly thereafter.
The battery group is 65N for a 2003 Ford Windstar
On the Ford Windstar 2001 model, it is under the hood, next to the battery.
Open the hood and look see.
get an engine diagnostic check, a lot of different problems can contribute to your situation.
In the grill area behind the battery
Anywhere from $50 to $150
alternator is not charging battery, or loose - corroded connection on battery cables
On a 2001 Ford Windstar : The Power Distribution Box is in the engine compartment , between the vehicle battery and the drivers side fender
I would suspect the vehicle speed sensorSee "Related Questions" below for more
The Power Distribution Box ( which is " live " ) is located in the engine compartment between the battery and the drivers side fender on a 2003 Ford Windstar
Facing the engine from the front of the vehicle, the battery is located in the right, front corner.
Sounds like a bad muffler bearing to me .......