Ford Repair: 2004 Ford Explorer XLT Temp Selector, ford explorer xlt, clip fastener

Question
Recently, as the weather changes and I find it necessary to use the defroster . . . I turned the temp selector from "blue to red" or clockwise.  Upon doing this, I hear what sounds like a "thumping" sound as if something is either not fully engaged (clip, fastener etc) or the temp mix damper door is stuck.

Is this a "DIY" type repair?  Does it entail the removal of the I/P?  Is it adviseable to have a dealer do the work?

Answer
Hello Kim, There is a door in the heater,a/c case inside the dash. What happens is the door will crack on the metal rod. The motor trys to move it but it slips causing the noise. The only to repair is the dash has to be removed to repair. Hope this helps Thanks Tony