Range of movement on my windsheild wiper arms are going crazy
 

When I work the wipers, on the first several swipes, the movement is ok, thereafter, they go out of sequence, and the drivers side even swipes beyond the windshield. Can/should/ and/ or how, are the range of movement corrected? Thanks.

Flip open the cover plate to the wiper arm nuts and check to see if they are tight. You may need to replace the arms if the knurling inside the arms is worn and not contacting the hold down screw tight enough.

Yeah, something sounds loose, and that would need to be fixed right away.

I had to rebuild my wiper assembly a couple of years ago. They would go where ever they wanted to sort of. I found the flat elbow that connects from one side to the other broken straight through the middle of the mounting hole. I got a good used assembly and put my new motor on it. I took the "new" one apart and lubed everything up then reassembled it with the new motor. Works great since then.

One of the exterior "cap nuts", the one on the passenger side, it appears needed to be tightened. I tightened it, and both arms appear to be working fine now.

One other question, after using the wipers, after immediate use, they do not finish at the very very bottom of the windshield, somewhat higher. I'd like them to finish at the bottom. Any solution to this? Thanks

re-position the wiper arm after removal