EATC Electronic Air Temperature Control. No matter where you set the system, the air would blow, willie nilly.. sometimes down.. sometimes windshield, sometimes dash vents. So I looked for all the obvious stuff, under the hood. Vac hoses and connections and Vac Can. I figured it was probably a Vac leak in the dash somewhere. I wasn't gettin into all that , and I was just about ready to call the Lady and send her elsewhere. So I decided to Google the problem. Found out that there are o rings inside of the controller that are a know problem.