Im looking for a little advice. I have a 2005 F150 and the ac is not working properly. The ac temperature is fine however the ac only blows a small amount on high. If I hit, what I believe is the blower motor casing under the glove compartment, with my hand it will blow like normal until I turn off the truck. However when I start it again it goes back to barely blowing at all. I have read through the threads on here and I dont believe it to be a resistor problem as it seems that people with resistor problems experience symptoms where the blower blows correctly on certain settings. My ac blows on all settings, however on all settings the volume of air coming out is extremely reduced.
I am planning on changing the blower motor unless someone tells me to check something else first.
Any advice is greatly appreciate. Also Im no mechanic by any means. How hard is it to change the blower motor?

 

Maybe the door that controls the airflow is not functioning properly or you have a little lick in your vaccum so it don't pull the door properly