Econoline E350 1 Ton V8-5.4L SOHC VIN L (1999)
selector position determines heating or cooling and air distribution. The temperature blend control setting determines air temperature.
The manual climate control components are used to:
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select air inlet source (outside or recirculated).
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select blower motor speed.
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select discharge air temperature (temperature blend).
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select discharge air location (defrost, panel, floor).
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select A/C compressor clutch operation.
Climate Control Assembly
The climate control assembly has three system controls.
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The A/C heater function selector switch combines a vacuum selector valve with two electrical switches to supply battery positive voltage to the
A/C clutch circuit and the blower motor control circuit.
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The temperature selection is accomplished with a potentiometer connected to the electric blend door actuator that controls positioning of the
temperature blend door. Movement of the control knob from COOL (Blue) to WARM (Red) causes a corresponding movement on the air
temperature control door and determines the temperature that the system will maintain.
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The blower motor switch controls blower motor speed by adding or bypassing resistors in the heater blower motor switch resistor.