Maaring madumi yung blower fan kagaya ng sinabi ni ghost....Pwede rin yung blower fan motor mahina na ang ikot dahil sa:
1. Carbon brush wear
2. Rotor bearings
3. Field winding
Better to buy a surplus blower motor than to repair (sa akin lang naman po). Tapos pa-install mo sa mga aircon shop na kakilala mo.

Hope this helps....