I believe my heater/AC motor my be going out but I am not sure. It works sometimes but tends to start making a rattling noise when i slow down or come to a stop and than stops blowing air. It will blow air out really well and than blow very little air if any at other times. Would anybody know what I should check to see what I need to replace.

Answer: Yes, it does sound like the blower motor is starting to go bad. That would explain the noise. Another common problem is a part called the "blower motor resistor." This will cause blower motor speeds to stop working, or only a few to work, but this will not cause any noises. The noises are the bearings in the blower motor itself. I would get that replaced, then make sure that all speeds can be controlled.