Heater fan in 1991 Pontiac sunbird stopped working. We have replaced fuses, and the fan motor. Still not working, continues to blow the fuses. What to do?

Replace the blower motor resistor assembly. To locate the electrical connector for the blower motor resister, it is usually attached to a heating or air conditioning Duct, or the blower motor case. You can also trace the Purple Wire from the blower motor back to the resister. Also make sure that the blower fan is not jamed up with somthing in side and will spin freely,or binding same thing, this will also cause the fuse to blow right away. And does the motor actually spin a bit before it blows the fuse or does it blow the fuse at the same time the switch is turned on? Good Luck and have a good XMASS.