I have been having a problem with the wipers for a while. If i turn them off while they are in motion they will stop wherever they want to usually in the middle of the windshield. If I quick flip them off when they are all the way down they will stay down. If I have them on intermittent they will stop 3/4 of the way down, pause for intermittent then go all the way down before they go up and then keeps repeating this. Any thoughts?