I'm posting this info up for future reference for anyone experiencing problems with their interior heater a/c fan.

On my GDB my fan speed grew weak, then only worked on max, then stopped altogether. Having had this problem with a previous car (non-subaru), I immediately thought it was the blower motor resistor.

Subaru quoted me $552 for part number 73533FE000. Interestingly, it is maker stamped nissan, so I googled and found similar blower motor resistors from nissan pathfinders. I never tried so i don't know if the cross make parts are compatible.

Ebay found me a suitable replacement from JDMspares for about $80 shipped. Conveniently it came as a complete unit (blower motor, resistor and complete housing).

As I thought it was merely the resistor, i swapped out the resistor. Fans worked, but weak. Some googling revealed that sometimes the resistor goes bad first, and at othertimes the fan goes bad first.

I swapped out the entire blower unit and now all is good.

The swap out job isn't difficult but quite finicky.