The heater control valve on a 1999 Chrysler Cirrus is located
inside the passenger compartment, under the dashboard. It's not easily accessible without removing parts of the dash. It's part of the HVAC (Heating, Ventilation, and Air Conditioning) system and usually connected to the blend door actuator.
You will likely need to consult a repair manual specific to your 1999 Chrysler Cirrus to get precise location instructions and understand the dash disassembly procedure. This is a job best left to someone experienced with automotive repair, as improperly removing the dash can cause damage.
