The heater core and blower on most models are contained in the heater box (fresh air housing) located in the center of the passenger compartment under the dashboard. On most air conditioned models, the evaporator is located in the heater box. On air conditioned Dashers and most Quantums the evaporator is located under the hood separate from the heater box.
The blower fan on non-air conditioned models before 1977 is open bladed, much like an airplane propeller. The blower fan on all air conditioned models and non-air conditioned models after 1977 is of the turbine type.
On some models, the fan and core can be removed without removing the heater box. The fan should be accessible from under the hood on these models, while the heater core is accessible from inside the passenger compartment.