Manual Climate Control System
WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The manual climate control system operation is determined by the settings on the climate control assembly. The climate control assembly includes a serviceable function selector switch and blower motor switch. The temperature control switch, A/C request switch and rear window defrost switch are integral to the climate control assembly and are serviced as an assembly.
The blower motor switch:
- sets the front blower motor speed.
- directs the blower motor path to ground through the blower motor resistor to allow blower motor operation in LO, MED LO and MED HI.
- actuates the high speed blower motor relay, giving the blower motor a direct path to ground which allows the blower motor to operate in HI.
The temperature control switch:
- is a potentiometer that outputs a variable voltage to the temperature blend door actuator to set the position of the temperature blend door.
- initiates closing of the heater control valve. When set to full COOL, a lever on the temperature blend door pivot shaft depresses the pintle of the heater control valve vacuum switch. The heater control valve vacuum switch then applies vacuum to the heater control valve, closing off engine coolant flow to the heater core.
- is serviced only with the climate control assembly.
The function selector switch setting:
- determines where the system airflow is directed.
- enables blower motor operation.
- enables auxiliary blower motor operation, if equipped, by supplying voltage to the auxiliary blower motor relay.
- commands A/C compressor operation in MAX A/C, FLOOR/DEFROST and DEFROST.
The A/C request switch:
- can command the A/C compressor on when the function selector switch is in PANEL, FLOOR/PANEL and FLOOR when the A/C request switch is pressed.
- is inoperative in MAX A/C, OFF, FLOOR/DEFROST and DEFROST.
- indicator illuminates when the function selector switch is in MAX A/C and cannot be toggled.
- indicator does not illuminate in OFF and cannot be toggled.
- indicator does not illuminate in FLOOR/DEFROST and DEFROST and cannot be toggled. The A/C compressor will operate if the outside air temperature is above 6°C (43°F).
- is serviced only with the climate control assembly.