Your tab is not seated all the way. The tab is stuck or the arm is not pushed down as far it can go to let the tab seat. Remove the arm and check the splines for any obstructions.

 

Here is a link to DIY Flip Up Wipers.


https://www.cherokeeforum.com/f2/diy...wipers-191912/

 

You lost me.

Maybe grab some out of the boneyard and give this a try.
My first thought is the part of the arm that the wiper blade attaches to can't pivot
because the gap in the bigger circle in the picture I posted needs to be bigger
to clear the part the tab is in. Thing is if that is the case will the spring let you
fold it all the way up.

 

This is mine.

 

I think you are missing the point. That is what I think somebody was saying to keep the wiper of the windshield cause they don't fold all the way up.