The heater core is located in a case under the dash, and is connected into the engine cooling system. It is usually made of copper or aluminum and consists of tubes to carry the coolant and fins to transfer heat to the passenger cabin. As the coolant circulates through the core, the blower motor blows air through the core, warming the interior. If testing proves that your heater core is leaking or clogged, please contact us freely, our engineers will supply detailed suggestions for your replacement.