Turned out to be the Fan motor itself. It would run for the first couple of heat cycles or the first few times with the SLP fan switch. What I believe to be happening was the fan motor would heat up after running and eventually build up enough resistance and not be able to run. 40 bucks and it now nice and quiet and runs whenever!

 

YOu just replaced the fan motor or the fans?

 

Just the motor, autozone had one in stock for 40 dollars with a 3 year warranty.
It is simple, remeber I only have one huge fan that has one speed,
You have two! They have a hight and low! I like that better.

 

OH i see, yes i have two......

Good job on the fix!