I have the same problem with my 1997 Pontiac Transport. I live in the snow belt and had to leave my car unattended for a spell so to turn the engine off while the wipers were working so as to leave them in a vertical position thereby preventing them from being trapped in snow and ice had I parked them in the normal off position. After that they now park up instead of down (horizontal). I bookmarked the question page. I will try to give you my solution to the problem once I discover it.
I fixed my 1998 Pontiac wipers by removing the plastic cover over the motor and spraying the disks where the arm attaches with brake cleaner. Seems to park the wipers correctly their must be enough friction to cause the "park mode" to be engaged when the motor runs backwards (which is what it does to park the wipers). Adding grease make it worse, so I removed all grease with the spray from the brake cleaner, especially on the little spring the wraps around all those little plates.
A bad motor can cause the driver side wiper to be slower than the passenger side. If one side is slower than the other, the blades can get stuck on each other.
Specifically:To change the wiper blades, lift up the wipers and underneath you will see a "lever" where the wiper blade mechanism attaches to the wiper arm. Depress this "lever" type mechanism and the wiper will slide off. Sometimes they get stuck so you may have to keep working with them to you get it loose.Mine was pretty stuck, so I tapped gently on the outside end of the blade mount in order to get it moving. As soon as it released it was easy to complete the exchange.
the park tab is bent. it is a thick piece of metal that must be bent back slightly toward the wiper motor with a hammer or plyers. I assume this issue started when there was snow/ice on the windshield?
Not sure if you're stuck on Bosch, but the one listed below in sources and related links snaps right on.
Wipers don't stick if it wont move that means the wiper motors have froze up as in quit working all you can do is try to get the wiper motor working by turning the wiper switch on and grab the wiper arm and try to move it up or down if that don't work remove the wiper arms then remove the cowl and replace the wiper motors
my Pontiac keeps getting stuck in park
The first thing I would do is make sure you have the right size wiper blades on the arms. The 2006 Chrysler Town and Country takes 28" wiper blades on both sides front. (the rear takes a 16") When buying windshield wiper blades be sure to always use the application guide book at the store, or now-a-days you can Google 'lookup wiper size'. You want to look this up because correct wiper fit is more than correct length, it's also proper attachment. Not all attachments fit all arms. Using the application guide or looking up wiper size online will avoid headaches of buying the right lengths with the wrong attachments. If the problem is beyond this answer, its beyond my knowledge.
Use an Easy out bit, (you'll find at your hardware store). Got mine stuck just yesterday
How do yo fix a stuck driver side electric window on a 1998 pontiac firebird.
They could be stuck together if it's real old, or the blades aren't connected properly to the engine.
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Wiper parking switch faulty, most often part of wiper motor