Central System Cooler Ball Bearing Fan Deep 6.5" Long 40 CFM "unit blowing hot heat" Questions

...unit blows out cold air between the hours of 6p and 6a. NO matter how high I set the thermostat. Why? After 6am when I manually adjust the heat to a high temp hot air blows out...Please help!! Throw ...

...unit so you can work on it, on a solid surface. Remove the access panel and make sure ALL the fans\blowers are running and if any have been removed, that they are blowing in the proper direction. If ...