Lisa looked over the situation with the intermittently-failing heater/AC fan on my van today. The fan stopped working again while we were in Portland and didn't come back on again. She's found what she thinks is the problem, and also thinks she may be able to fix it. If it's what she found, I don't see how the dealership could have missed it, as it seems relatively simple, in the form of a loose/damaged power connector to the fan. Assuming we proceed with the repair, we'll document it in photos.