First thing to check is that the arm has not come loose on the motor shaft. Tighten it up before rushing out and buying a new wiper arm (like I did).
Otherwise, look at the blade itself for wear and age - it could be the problem with keeping adequate pressure on the glass.
Last is very gently putting a little extra bend into the arm shape itself. Just be careful to not stress the wiper motor shaft. The safest thing to do would be to remove the arm while re-shaping it - remount and test.
Replace the windshield wiper arm - it has a spring in it to apply pressure to the windshield - if the old one is not applying enough pressure it is probably broke They are available at most auto stores
There are 2 wiper motors on a Windstar: 1 for the front wipers and 1 for the rear.
A electric motor that moves the (window) wiper to clean the window.
Most likely your wiper blade needs replacing. Before replacing however, you can check to see if the arm moves freely away from the window and if there's good pressure back towards the window. You can also see if the wiper blade moves freely on the wiper arm and that its not binding. If both of these checks seem ok, then its probably just a worn wiper blade.
You don't, if the wipers are loose on the window, you need new wiper arms and blades. If your wipers are old, they will be dry-rotted and will not form to the glass as intended. You can try new rubber inserts first, that's the cheapest way to go. If that doesn't work, replace the arms and blades.
Its easy once you get the correct rear wiper blade - the new wiper will have installation instructions. Can't really answer this question without year of the Ford Windstar. See sources and related links below to lookup the correct wiper blade.
2 different systems being asked about.See "Related Questions" below for more about both
The 2002 Ford Windstar takes 24" driver side, 20" passenger side and 16" rear replacement windshield wiper blades.
The rear window wiper/washer control is on the turn signal 'stalk'. It's the inner-most controls that rotate in both directions, with washer spray rotated all the way towards the driver.
The 1996 Ford Windstar takes 24" drivers side, 20" passenger side and 16" rear replacement windshield wiper blades.
sounds like the park switch in the wiper motor. (needs new wiper motor)
the wiper dont work