96 Volvo 850 GLT-Defrost air vent isn't blowing out when I turned selector(control ****) to defrost but always both sides and middle vents blowing not defrost or under dash(floor) vents though I already replaced blower motor and resistor. Speed control and temp(heat/cold) works fine. Changed to different choices but seemed the same, I guess.(it's manual) What will I need to do? Thanks and appreciate!

 

i have heard that the plastic arm can break that controls the mechanism to switch between areas

 

You'll need to pull the head and see if everything is connected and if so follow the cables and see if anything at that end is disconnected or broken.