Cadillac Repair: cadillac heating problem, vacuum problem, cadillac deville

Question
I have a 1990 cadillac deville and there seems to be a problem with the heater...whenever i turn it on it just blows through the floor vents and through the defroster vents,but i can't seem to change the settings to blow through the front panels..i've heard something about maybe the codes need to be reset, but i don't have the owners manual and i don't know how i would do that, or if that's the problem...also whenever the engine is idling the heater blows cold air..does that mean i need a new thermostat?  Please help..any suggestions you can give would be greatly appreciated!

Answer
There is NO CODE RESET for this problem. You either have a vacuum problem within the AC/Defroster PROGRAMMER and or a faulty actuator door.

Check the level of coolant in your radiator and in your over flow jug and make sure that they are at the appropriate levels.