I have a Comfortmaker NTG3075FBG1 forced air system. Before yesterday, I had no issues with heat or A/C. Now, when A/C kicks on, everything sounds "normal" (short delay, outside compressor comes on, air handler blower starts). However, at the floor registers I can feel almost no air coming out. A little research tells me its a 1/3 HP 4 speed motor (HQ1012514EM). I was at first thinking I lost the "high" speed. The problem is that I do hear the motor running, and I feel air flow in the plenum. If a "speed" fails, does it default to a lower speed? Any ideas on this before I start taking things apart?