Auto Air Conditioning & Heater Repair: Heater, rheostat, fan motor

Question
I have a buick 1984, the heater works fine, but no air blowing, and I test the blower motor it works fine. I need your help. thanks

Answer
Hello
If you have tested the blower and there is power to it, can you make it run if it is unplugged from the vehicle and you give it 12 volts ?
If it is getting power that way the fan should go full speed.If it won't run then it is the fan motor or worn brushes if you have them.
When it is connected to the vehicle the speeds are controlled by a rheostat. This limits the voltage to the fan, usually 3,6,9,12 volts.
By turning the fan on to full it should bypass the rheostat and run full speed, if it doesn't then I would suspect the motor itself or the wiring between the switch on the dashboard and the fan motor

We are a UK company with limited knowledge of your particular type of vehicle and can only provide very general answers to the question but I hope it helps

Thank you for your enquiry