I have this tapping or clicking sound coming from my dash board on my 2007 Mustang, I took down the glove box and looked in behind the dash board and saw what they call a Blend Door Actuator, anyway I think there are two of these one upper and one lower behind there. My question is has anybody changed a bad one and how hard is it to do it the part cost $22 but I don't want to start taking it apart and I have a mess. This is a picture of it.

I think this is the lower one under the other one.

 

I had the same issue with the blend door on the passenger side. Check out my post...

https://mustangforums.com/forum/2005...-actuator.html

They're pretty easy to replace if you can get to the screws that hold them in.