Cadillac Repair: 91 Cadillac Eldorado heating problem, cadillac eldorado, air switches

Question
For some reason the heat will not blow out the vents on the dashboard, no matter what setting I have it on. Heat will blow out of the defroster and the floor. When I turn it above 72 degrees the flap closes behind the vents, I can see it close. I have replaced the auto climate control module and I have brought it to the cadillac dealer, but they didnt know what it was. Is there a temperature module that controls that flap behind the vents, or is that flap controlled by the climate control module? What controls that flap? Is the climate control module the part where the buttons are or is in the dashboard. The flap lets the heat blow out the vents on the dashboard, when that is closed it blows on the floor or the dash. Any ideas? I have replaced the radiator because of a leak and replaced the thermostat at the same time.  

Answer
Hi Michael, On your Eldo once you get in the 72-75 range the air switches from the vents to the floor so you will never really get heat to the vents but will allow heat to the windshield to help melt the ice and snow or warm your feet...remember hot air rises so the engineers figured that you would rather have warm feet instaed of cold feet. On the newer caddys there is an override button that you could get heat from the vents but that is around '96 or so. Heres how the system works. The climate panel sends a signal to the programmer about what you want the air to do and the temp of the air. The programmer recieves this signal and sends vacuum  to the motors to control where the air goes and an arm on the top controls how hot the air is. The programmer is located behind the glovebox area. There is an adjustment screw on the programmer that can change the temp. aprox 4 degrees but there isn't anything that can be done to change when the air goes where it goes. That is controled by the body computor. If the air should be out the vents at 70 say and it comes out the floor or windshield then there might be a problem with a vacuum motor or programmer. My advice is don't buy anymore parts because your car is operating as designed. Hope that makes sense. There will be a test on friday. LOL. Class dismissed. Bill