When I have my temp. control knob to heat, there is significantly reduced airflow. It gets very hot, it just doesn't have the same airflow as on cold. Is this normal?
Is that how they make it so the floor vents put out hotter air than the dash vents when that mix option is on?Ya, sounds like the heater core is blocked, maybe by paper or some other debris. When the temp is set to cold, the heater core is bypassed by the air, but as you move it more towards hot, more and more air goes thru the heater core, until at full hot, all air goes thru it. So if the airflow decreases as you increase the temp, then something is restricting airflow thru the heater core.