Hello,I am a retired mechanical engineer with 56 years in this business. I will go in depth with you, and up to a 6 hour time limit.
All I ask is please select the ***RATING LINK*** at the top of your page before leaving, that is the only way I am credited through the site.
Rating does not affect your charges nor ability to refund if not satisfied. If you can agree to that, lets continue by all means.
I need the brand and model number of your furnace to determine if its a variable speed motor, or a 3 speed motor. If its a 3 speed motor with a cigarette sized metal capacitor mounted on the blower housing, replace the capacitor... take it to Grainger industrial supply or Johnstone Supply for a match up, if that fails the motor is bad.
IF the motor is a variable speed type things get a lot more complex, tell me a lot about your technical skills so that I can coach you most effectively. Variable speed motors have no capacitor and they have 8 to 14 wires attached to them instead of just 4 wires.
We can go from here when I get back from lunch or you can opt me out if you do not want to wait.