Heater blend door actuator

Is the coolant level full ? Are the heater hoses hot to the touch ? Do you know where the heater hoses are ? Out in the engine compartment going through the fire wall into the passenger compartment . 2 hoses , one carries hot coolant into the heater core the other is a return back to the cooling system . If hoses are hot you have a temp. door not working . When warmed up what does temp gauge show ?
Temperature Control
The temperature control operates in the following manner:

• Temperature control of the manual A/C-heater system is determined by the position of the temperature control knob (between COOL and WARM).
• This control knob is connected to a potentiometer mounted in the integrated control panel. This potentiometer is electrically connected to the A/C electronic blend door actuator that operates the A/C air temperature control door.
• The A/C electronic blend door actuator contains a reversible electric motor, another potentiometer and a printed circuit board. The wiper of the potentiometer is connected to the actuator output shaft and moves with the output shaft to indicate the position of the A/C air temperature control door.
• Battery voltage is applied to the ends of each potentiometer. The voltage available at each wiper indicates the position of the potentiometer. The printed circuit board drives the actuator in whichever direction is necessary to make the actuator wiper voltage agree with the control wiper voltage.

System uses a reheat method to provide conditioned air to passenger compartment.

• All airflow from the blower motor (18527) passes through the A/C evaporator housing where it can be cooled and dehumidified.
• Temperature is then regulated by reheating a portion of the cooled dry air and blending it with the remaining cool air to the desired temperature.
• Temperature blending is varied by the A/C air temperature control door which regulates the amount of cooled air that flows through and around the heater core (18476), where it is mixed and distributed.

In all modern cars there is a tiny DC electric motor driven gear drive that moves a plastic door that blends heated and cooled air from the AC and the heater core, this is called (interestedly enough) the air temperature control blend door actuator. The motor that moves this door fails because the door starts sticking from warping, most common complaint is no heat but it can be no AC as well. To replace these parts (blend door and blend door actuator) you must remove the entire dash from the car. Always have this problem confirmed by a dealer or qualified repair shop as it is a very expensive repair.

In a Ford 90's and up this is caused in most every case by a defective air temperature control blend door and the electric actuator that moves the door, the blend door is located deep in the dash between the heater core and the AC core, it mixes or blends the air from the hot heater core with the cool air from the AC or outside air. The blend door is plastic and they get warped, then the actuator that moves it can't move the door due to the warping of the door and it fails from the strain

if the heater hoses are both hot its a blend door actuator, and possably the blend door its self, the way to make sure is to feel around under the dash . feel the black hvac box and if its feels warm then the heater core is good, you will have to remove the dash to replaced the bland door actuator and blend door ,i reccomend you replace both beacause its alot of work to remove the dash so make sure both components are replaced while you are in there

a clogged heater core, a bad temp blend door actuator, or a damaged temp blend door

It is most probably the problem with blend door or blend door actuator. But just in case I would suggest to follow the entire procedure:

First you have to identify what causes the problem.
To do this you have to:
1) When engine is cold check the level of coolant. If it is low fill it up.
2) Start engine and check if engine reaches regular temperature. If your engine is not heated enough it means your thermostat does not work properly and should be replaced
3) If engine temperature is normal, then check the temperature of pipes that go to/from heater core. These pipes are located up the fire wall (easier access is from the passenger side). If pipe/pipes are cold (even engine is warm) it means you heater core is plugged and should be flushed. Keep in mind, flushing the whole cooling system is different from flushing heater core.
4) If pipe/pipes are hot/warm, turn off the fan, switch controller to the hot position, wait for 3-4 minutes and turn on the fan. Note if the cold air blows first or warm air blows first but it cools down in 5-10 seconds. If the air blows cold than it is most probably the problem with blend door or blend door actuator.
5) If air blows warm first and then cools down, then while running engine and remaining the transmission in PARKING position, press on the gas pedal until your engine reaches 3,000 RPM. Check if your heater blows warm/hot air. If it does, then your water pump does not work properly and should be replaced. If the air still cold, I would suggest flushing the heater core.

Is the heater working? Turn the A.C. off with the car at an idle. Turn the A.C. on and listen for the compressor to turn on. (should hear a click under the hood and the motor should change pitch. If no noise, the compressor is not comming on. The o-rings were bad about leaking on these cars, letting out all the freeon. If there is no freeon, the low pressure switch won't let the compressor run.

Likely it has more to do with the door that controlls the airflow. Which should be operated by vacum might check and make sure all thevacum lines are plugged in.

Does the gauge in the car show it warms up?

Item Part Number Description 1 — Air inlet door 2 — Temperature blend door 3 — Headliner airflow 4 — Auxiliary mode door 5 — Floor airflow 6 18476 Heater core 7 19860 Evaporator core 8 19805 Blower motor
The auxiliary A/C and heating system has the following features:

• The auxiliary A/C and heating system is functional whenever the instrument panel mounted A/C control is in any position except OFF.
• The auxiliary blower motor recirculates the air inside the vehicle. Outside air is not available to the auxiliary system.
• Air is cooled and dehumidified by the auxiliary A/C evaporator core only if the instrument panel mounted A/C control is adjusted to a position that requires A/C compressor operation.
• The temperature blend door and the auxiliary mode door are controlled by electric actuator motors.
• Movement of the auxiliary temperature control between COOL and WARM causes a corresponding movement of the temperature blend door to mix air flowing through and around the auxiliary heater core.
• Movement of the auxiliary mode control between PANEL and FLOOR causes a corresponding movement of the auxiliary mode door to direct air flow between the panel (headliner) registers and the floor duct.

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I would say the auxiliary mode door (#4) electric motor is not wokring.

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Auxiliary Blend Door Actuator —Air Distribution Removal and Installation

1. Remove the RH quarter trim panel cup holder and access panel.

1. Remove the screws.

1. Disconnect the blend door actuator electrical connector.

1. To install, reverse the removal procedure.