DHC8pilot

My 2005 Escape does not blow through the vents when I turn the selector knob to heat. If I start on the AC side it blows fine, then as I rotate it through the 12 oclock position, the air flow diminishes until when it's on full heat, it barely blows at all. I can hear the air resistance going somewhere, just not out the vents. Was told it's the "actuator". It does sound like some butterfly valve in the system is not opening to allow the heater air to flow. How accessible is this part, and do I have to take apart the whole dash to fix this.

Thanks

R.S.LOGAN

Probably is the actuator as advised , but on other cars I've had in with that type of fault ,the cabin filter needing replaced was sometimes causing restricted air flow .