Obvious question, but what RV?
We have a 2008 Damon Daybreak and our problem was the passenger 'overcentering' and falling down, jammed mechanism and no wipers.
What I found was two parts of the mechanism bent. One, which could affect either side is the crank or actuator on the motor, small bent plate. The piece that bolts to the motor and the part that connects to the two rods should be parallel, ours was seriously bent causing a longer stroke, wiper throws further than it should, off screen in essence. To make matters worse the pivot and shaft on the passenger side was also bent, pivot should be 90 degrees to shaft, ours ended up somewhere around 120 degrees, again this increases the stroke so wiper can get off screen. Both parts easily removed and straightened and after much reading, mainly irv2, I changed out the 32" blades to 28". System now working just fine, which is fortunate as a few recent trips have been in rain.
Si, Sarah and Shelby the westie
2008 Damon Daybreak 3070
98 TJ, 4" lift, 31s, usual stuff