Might not have been the blower fan that was the problem.
Heat for an air cooled Beetle came by way of square tubes that drew air across the exhaust manifolds. Said tubes were the edges of the floor pan, right behind the running boards. These were famous for rotting out, so you wouldn't get optimal airflow, and a bunch of it was just outside air anyway. The heat exchanger bits on the exhaust manifolds would also rust away, making for the same problem.
Then, when you have to drive to work in an ice storm in your Beetle with no heat, and the windshield is completely obscured, you have to just stick your head out the window. When oncoming traffic passes you, you jerk your head inside again, blinded and surprised, and quickly wipe the slush out of your eyes. You still can't see, and realize it's because of the aforementioned windshield thing, so you stick your head out again.
Here comes a bus. "Welp, I'm just gonna have to take it."
Ahhh, 1992.