Windshield Wipers Stuck Together - Why?

I’ve searched around the web and haven’t had much luck with this question…I think it required a bit more of an explanation vs. typing some key words into Google.

I have a 2004 Mazda 3 Hatchback. Just over 118K. I was driving home in the Oregon downpour yesterday when my windshield wipers got stuck together. There must have been a lapse with them or something - I had to pull over and literally PULL them apart, and the entire arm of the wiper (both sides) bent pretty seriously. I ended up just taking my passenger side one off to get home.

Any ideas of what causes this? I bought the car used, haven’t had it long enough to even replace the blades - but now I get to replace the whole thing and probably more.

Thanks for any ideas!

Remove the wiper arms and check to see if the splines in the wiper arms are stripped out where they fit onto pegs. If they are, the wiper arms are slipping on the pegs going out of sync and they eventually hook together.

The fix is to replace the wiper arms.

Tester

As Tester suggest. If they striped, make sure that both parts are in good condition. If either half is stripped, the other can stripped easier.

One of them came loose at the pivot. A new wiper arm has no teeth in it and when you nut it down to the pivot those teeth bite into the arm end. But over time they may loosen a bit or the arm may have been forced over ice or debris and caused enough stress on those teeth to strip.
A new wiper arm should fix it.

That is one of the reasons to ALWAYS clear off the snow and ice BEFORE operating the wipers.

It immensely irks me to see those stupida$$ commercials that show anyone using the wipers as the FIRST step in clearing off the snow.