My old 2001 Sierra had wiper arms that you could pull up and they would stay off the windshield. They locked into place and it was great because you could do this when clearing ice/frost/snow off of the windshield. It also made it a lot easier when you knew freezing rain was coming.
So, what did they do to the 2004 Sierra? Well, they made it impossible to do this now. Heck, you can barely pull the wiper up enough to get a snow brush under it. The hinge now has a solid metal piece that prevents you from flipping up the wiper. Well, at least I’ve been unable to flip mine up. The old truck didn’t require any force so I don’t really want to pull hard on the new ones.