A little late to this, but FWIW to get mine freed up I used air tool oil with it in the truck - put some in the line and used some regulated air pressure (light pressure) to push the oil in; gently coaxed the wipers to move and eventually got it working like a champ. That was over a year ago and they worked great all fall. They get a lot of use up here, and ya I know going uphill is always a challenge but I get a kick out of them. The truck had been parked since 1998.
I'd suggest running the stock wipers & blades too, when I got mine the truck had some heavier arms and wiper blades on them - reading a little on it they may create too much friction for these; and certainly with the lighter stock setup they really move well.
