Iv noticed that my floor vents don't seem to put out the same amount of airflow as the dash or defrost vents. I have to put the fan on 4 in order to get the same amount of flow as the dash or defrost vents on 1. Is this typical? It seems that in order to heat the truck, i have to run the defrost till its warm, and then switch it to floor.

 

Seems about right with just about every vehicle I have owned?

 

I have the same thing. if you make sure the dash vents are all closed it will help.

also, some heater air is diverted to the back seats thru a vent under the driver and passenger seats. maybe close these off somehow??