No Defrost

Hello
I have a 2013 Tundra , Defrost does not work , turn the knob to defrost and you can hear air moving but nothing comes out of defrost . Mechanic said cable came off, tried putting a shim on there so the cable does not come off. But it did and dealership they want to change whole unit . Where is the cable located , it sounded like pretty close to the brake pedal but I can not see the loose cable that probably came off . Anyone have any pictures of where it may be located so I am looking in the correct spot .
Thank you

 

Look up ac servo motor. Iirc that should show you where all the cables are located.