Where is the heater core in a 1999 Mercury Mystique?

In a 1999 Mercury Mystique, the heater core is located inside the dashboard, typically on the passenger side. To access it, you'll need to remove the dashboard components, which can be a labor-intensive process. The heater core itself is situated within the HVAC housing, connected to the vehicle's cooling system. Make sure to properly drain the coolant before attempting any repairs.