72 A/C,heat,defrost blower stopped working?

[cherokeejohn]

So on my 72 350/th350 factory A/C truck, the blower just stopped working this past week. About a month back, I took my diverter box out, cleaned and greased it, replaced gaskets, cleaned all vents and ducts, and reinstalled it. The blower worked before this, and after it as well. This past week, we had our first frost here in the Mid-Atlantic area. i went out, started her up, turned the defrost on, turned the fan on high and let her warm up. come out just shy of 10 mins later and it had only defrosted a area the size of a baseball. i felt the defrost vents and i can feel heat, just no force behind it, flipped the fan switch a few times, i can hear a noise coming from behind the diverter box or the glovebox (cant determine exactly where. but i can hear it trying to do something. I've researched a bit on it and it is between the fan switch, the blower motor, or a resistor . any help or info on this would be great if anyone else has experienced this problem or similar. I don't want to just start buying a buncha parts and spending un-necessary money chasing a gremlin. this truck is my DD and WINTER IS COMING FAST. defrost is a must have.