Ford Repair: Knocking noise in my 2005 ford explorer, clunk, ford explorer

Question
Just recently when I turn my car on I hear this constant knocking noise around the passenger dashboard.it is continuous now my heater doesn't work.does this sound familiar to you?

Answer
yes, the blend door actuators go bad. it keeps trying to close the door so you will hear a continuous clunk.  it is actually located to the right of the driver's right foot. depending on who does the repair, they may tell you the dash has to be removed. which by the book it does but, if you've done a hundred of them like i have. it can be done in about an hour or so.