Figure I'll add to this thread incase anyone else is searching through the archives for a solution.
I had the same problem with the heater fan. After checking the fuses, fan speed resistors and seeing that the fan motor was getting voltage I assumed it was the motor itself. I pull it out (it's under the glove box to the right, only three screws, one's in a tight spot). I tested it one more time with the motor in my hand and it worked!
I can only assume there are two possible solutions. The connection was a little corroded and the multiple times I plugged/unplugged it I cleaned the contact surfaces or there was a small twig snagging the blower wheel (there were several inside it when I pulled it out.
Hope it helps future members,