The dealership called this afternoon while I was on the phone with Lisa. My van was ready to be picked up and they would send their shuttle over to fetch me. Not too long thereafter, I had my van back and the dealership had their $565, mostly in labor. (The part itself cost about $115, but I'm paying for them having figured out the problem as well as actually replacing the part.) The new fan runs just fine, and much quieter for the same airflow as well, so that's a good thing.