Blend Door Actuator question. I have a 2013 f150 5.0 the blend door on the passenger side keeps going bad every year or so. I'm on my third Actuator, two were aftermarket and final this one is oem. When the key is on, engine is off I can hear it keep roaming. I've done the rest process a couple of times. My question is could it be a tooth off? Is there only one way to install it wrong. Does the door have to be all the way closed or open?

 

There are a ton of threads about blend door stuff in the 2009-2014 section but most problems like hunting are due to blend door motor not recalibrating when key is turned on.
I had to have both blend door motors replaced recently so there are several bad actors with these symptoms. Might search and see what you come up with.