No not complete dash, most likely if there is no cable movement from the heat selector is that is has detached, never seen one break, jesus they are hard enough to cut when needing to, they're not unknown for detaching, you can laways take off the panel at the side that covers the area and goes rearwards towards the seat and move the flap manually this will straight away get you full heat and tell you what the problem is, 99.9% one end has popped off at the cable.
tabetha