No heat in passenger cabin

A blender actuator is the device, or flap, that controls where the air blows out, be it in your face from vents, floor, windshield and the knocking is probably that thing trying to go in to it's setting but not being able to. I think heater injector actuator is a fancy word he used to try and impress you, meaning flow control valve. 7 hours? I have not done that on a Nissan, but again all day?? That's probably what some guide says but.. he could do in 3, 4,,,5 if he wanted ti but at $75 an hour, who wants to hurry?