My heat blower motor on my unit in the attic burned up. I replaced the blower motor with what apex recommended 3/4 hp. My blacb wire for high in wired but hardly any air coming from vents. Worse, this new one is over heating and trying to burn up also. I didn't change the capacitor. What is causeing this motor to over heat. Also any suggestions on getting more air from vents? We are cold and I am frustrated.