When Your Car Heater Blows Cold Air
Crash Course in Car Heater Operation Most cars on the road have water-cooled engines, and their heating systems work on the same basic principle. Hot coolant from the engine passes through a heater core, which looks and functions like a small radiator, and a blower motor forces air through it. The coolant then heats the air, and the air, in turn, warms the interior of the vehicle. This is the reason that it takes a while for heaters to start blowing warm air....