codash

Just recently noticed since it started getting colder. When I turn the truck on, and when I reduce the temperature **** while the Heat is on, I hear a buzzing/clicking/humming noise. This only occurs when reducing the heat temperature. It has never happened before. A quick internet search shows others with the problem, but no diagnosis or fix.
Is this a vacuum issue?
Any help here?

codash

bump

mamonti

Not sure on a 2010 but they may have the same setup as 11 up. They use electronic actuators and they can start to go bad and make noice or the actual door inside that the actuators move can stick (which possibly scrap the housing)... Maybe something along that path is what I think is the issue!