Traction battery fan — how to tell if it's working

This is regarding a 2004 Prius. After approximately 260k miles (I say "approximately," as the combo meter was working only intermittently for a couple of years until I replaced it), I finally cleaned my traction battery fan. Yes, it was as dirty as you think it was. Maybe even a little worse.

Things seemed to go OK when I reinstalled the fan, so I hoped all was fine. But I can't hear the fan running, and according to Dr. Prius, the battery temperatures are 88-90°, which is coincidentally the air temperature in the car right now. I don't think the fan is running.

There are only two electrical connections to the fan, and I plugged both in. I don't know what else could I could have done wrong.

Does anyone know of a way of checking whether the fan really is working? I'd appreciate any and all suggestions.

Thanks in advance.

ETA: It's definitely not working. I'll check the fuses tomorrow, but I may just need a new fan. It is 22 years old, after all.