If an actuator binds inside the Hvac plenum, the control module will attempt to overcome the restriction several times before it shuts down the circuit. SYMPTOMS OF BAD BLEND DOOR ACTUATOR How do I know if my blend door actuator is bad? If the Hvac system loses power, or if a component is replaced, the endpoints must usually be relearned through a calibration process. The actuator endpoints will change as the door seal wears, so if the endpoint counts become too large, a DTC will be set. The Hvac control head, which has pre-programmed logic and actuator endpoint references, counts the electrical pulses as the motor moves the door through its sweep from one end to the other end. Two Wire actuators create electrical pulses when the commutator rotates across the brushes of the motor. There is no feedback to the control head with this design. When both voltage readings are the same, the actuator motor stops. As the motor moves, a potentiometer in the actuator compares the motor voltage to the output voltage from the control head. When a position change is requested by the vehicle operator, a circuit in the control head sends voltage to the actuator motor. These actuators use a preprogrammed logic chip containing all the information to drive the motor in the requested direction. Three wire actuators have a power, ground, and an input wire from the Hvac control head. These circuits are controlled by the Hvac control head and move the motor direction based on the selections made at the control head. The other two wires are the positive and negative circuits that drive the motor. Bi-directional Actuator Motorīi-directional actuators use three wires for circuit feedback. The other wires are for ignition voltage and Hvac control head requests.Ġ volts will move the motor one way, 5 volts will drive the motor in the other direction, and when the signal wire reads 2.5 volts, the motor stops rotating. Three of the five wires are used for the feedback circuit. This design allows for separate temperature settings on each side for the vehicle.Īctuator motors used in automotive Hvac systems can be one of four designs, depending on vehicle manufacturer, system design, year, and model of the vehicle:Ī tri-state actuator is a five-wire design.
TYRIAN 2000 LEFT STUCK DRIVER
However, most dual zone systems use two blend doors: one for the driver side and the other for the passenger side. The more air the blend door directs through the heater core, the warmer the air entering the passenger compartment.ĭual zone systems operate in the same manner as single zone systems. If the A/C is operating, the air is dehumidified and cooled. The Blend Door Actuator – the blend door determines the temperature of the air flowing through the passenger compartment. Single zone systems are usually equipped with three doors: The doors ay be controlled by cables, vacuum, or electrical actuators. The plenum houses the air doors and door actuators that direct airflow to the correct ductwork. It contains the evaporator and heater core, and the blower motor assembly and the blower speed control device. The Hvac housing is the plenum unit located and beneath the instrument panel. The air delivery system controls the movement of heated and cooled air into and throughout the passenger compartment. They were complicated for the time and often not reliable.
Most systems were equipped with a heater control water valve, also cable or vacuum controlled.Īutomatic temperature control systems had a range of controls: vacuum, electromechanical, and pure electronic devices. The control systems were cable actuated, and eventually, vacuum controls were introduced.
When A/C became a popular option on vehicles in the mid to late 1970s, the systems were simple, except for some high levels vehicles, which were often the test bed of things to come. As you adjust the temperature up and down, the signals go through the actuator to complete the request, positioning the air door on the right position. The blend door actuator is a small electric motor. When the Winter Season begins, and you try to change the A/C settings on the Air Conditioning Climate Control from Cold air to hot air and you cannot control the air temperature. Why my car A/C is stuck in heat mode when the cooling mode is on?Ī malfunctioning Temperature Blend Door Actuator Motor could be the cause.
0 kommentar(er)
