When I am running the A.C. and am stopped my car starts making a thumping or banging sound from behind the glove compartment. https://vimeo.com/105038686
The attached video has audio of the sound.
If it makes the sound with the blower fan on but the A/C off, it’s the blower motor and/or its fan blade.
If it only makes the sound with the A/C on, it’s an odd symptom. Might have a problem with the A/C compressor, refrigerant charge, or hose/pipe routing.
First thing that comes to my mind is a blend door problem (vacuum motor issue).
The cabin air filter and fan is behind the glove compartment. You can access it by dropping the glove compartment door down off it’s hanger.
If someone recently changed or cleaned the filter some loose debris may have fell in there like a twig. You can reach your hand in there (with the fan off of course) and see if there’s something rubbing the fan.
First thing that comes to my mind is that it’s a 2012 and likely still under warranty. If so, take it to a dealer.