Cadillac Eldorado heater issue not blowing air through vents, only defrosting windshield on Cadillac Eldorado

Some Cadillac Eldorado owners report experiencing issues with their heater not blowing air through the vents and only defrosting the windshield. This problem may stem from electrical issues, mechanical malfunctions, or coolant-related problems within the complex heating mechanism that relies on an electric fan and heater core. Additionally, some owners find that the hybrid system's vacuum and electric actuators may fail, preventing proper air distribution and defaulting to defrost mode under certain conditions. If air only comes out of the dash vents and does not switch to defrost or floor settings, it could indicate actuator or control issues. Problems with the heater valve, such as a vacuum close that is normally open, may also contribute to heating system malfunctions. Furthermore, a lack of refrigerant can result in only hot air exiting the vents, but if no air comes out at all, it may signal a more serious underlying issue. Prompt diagnosis and resolution of these factors are crucial for restoring proper heater function in the Cadillac Eldorado.