This may sound silly, but I too as a Minnesotan with an '05 Spectra5 had this very problem a few seasons ago. I looked and looked for any sort of issues but could not find the problem. Same symptoms: wipers work, plenty of fluid, and the motor makes a sound but nothing.
What ended up being the case was one of the joints for the hoses was actually broken from the hood slamming down on it (location-wise, it was right up by the windshield on the passenger side. I don't know how it got to the point where that could actually happen, but a quick trip to the auto parts store, and $.99 later, it was all fixed up. Bring the old piece in so they can match it to the right size.
The reason it's silly is I would run that thing when it didn't work and would never see any fluid spilling out. I think it was just positioned in the right spot so all the fluid I was pumping out was pooling somewhere in the engine compartment where I couldn't see it.
Hope that helps: it's an easy fix!