The blend door actuator may seem strange because it is not a common part of cars. However, it is an essential component of your car’s air conditioning system.
Therefore, when the blend door actuator fails, your vehicle will have noticeable symptoms.
You can still drive your car with a blend door actuator problem, but it can create discomfort for you inside the car.
In this article, you will learn everything you need to know to about your vehicle’s blend door actuator, what it does, the symptoms of a bad blend door actuator, and how to go about replacing a bad blend door actuator.
What Is a Blend Door Actuator?
The blend door actuator consists of a small electric motor in your car that controls your car’s temperature. This device resembles a small plastic box with several plastic gears inside. It is small and flexible enough to be held easily in your hands if you are trying to remove it.
However, it can be challenging to locate, especially if you’re not an experienced mechanic or technician.
The function of the blend door actuator is vital. The signal that comes from dialing to increase or decrease the temperature in your car goes through the blend door actuator. The defroster and other vents are also controlled by it.
Some modern cars have two blend door actuators, especially the back seat control temperature and airflow intensity.
What Does a Blend Door Actuator Do?
The Air blend door actuator comprises a plastic housing, a small electric motor, and a plastic gear set.
A sensor for sending feedback information to the climate control computer is also incorporated into the blend door actuator.
The actuator carries temperature and air direction doors into the heater plenum box designed to control mode settings like temperature flow, mod vent, defrost, and fresh air or recirculation modes.
The actuator also influences the right and left passenger compartment temperature settings.
When the actuator receives an electric command from your car’s climate control computer, it will start changing air direction mode.
The driver or passenger determines the direction of this airbase based on what they choose from the dual climate control systems.
Most car systems have three to four units installed at various locations around the HVAC plenum that are in charge of mode operation and are different based on the car make and model.
Where Is the Blend Door Actuator Located?
You can find the blend door actuator on the HVAC box underneath the dashboard. To determine the exact location of the actuator, the make, model, and year of the vehicle being serviced are taken into consideration.
Blend Door Actuator Symptoms
The following are bad blend door actuator symptoms
1. Knocking Sounds
Knocking sound is a common symptom of a bad blend door actuator. When you start hearing a knocking sound as you start your AC system, then it’s an indication of a bad or failed blend door actuator, and you need to replace it as soon as possible.
2. Wrong Temperature
When your blend door actuator stops working altogether, you might start getting the wrong temperature.
Depending on how well it is working, it will start to vent cold or hot air, according to the instructions from the control unit.
However, if you are still getting the wrong temperature despite adjusting the temperature for a few minutes, this indicates a malfunctioning blend door actuator.
3. Clicking Noise
When you start hearing a clicking sound from your dashboard, it could be a possible sign of a bad blend actuator.
The intensity of this sound could be faint, but it will be constant. You will notice the sound strongly around the HVAC control on your dashboard.
Get your car inspected by a professional mechanic for a proper fix when this sound surfaces.
4. Inconsistent Airflow
When you start noticing inconsistent airflow from your car vent, it could mean your blend door actuator has become faulty.
This occurs when the blend door starts moving back and forth rapidly or inconsistently, resulting in inconsistent airflow.
5. Any Other Strange Noises
You can also notice other unusual noises within your dashboard, and it could be a possible sign of a bad blend door actuator.
When you start hearing droning or squeaking sounds coming from the center of your dashboard, especially when you take a turn or change the temperature level of your air conditioner, don’t hesitate to call a professional when you start hearing such unusual noises.
6. Inconsistent Temperature
When you notice that the temperature coming out from your car’s vent is changing consistently and repeatedly without you touching or changing it from the control point, then this could mean that your blend door actuator is no longer functioning correctly.
Also Read: Radiator Repair Options And Which You Should Choose
Can I Drive With a Faulty Blend Door Actuator?
Yes, you can drive your car even if you have a faulty blend door actuator; however, we don’t recommend that you ignore it or let it continue for a long time.
The blend door actuator will not affect your driving because it is just a comfort feature inside the main cabin.
However, if it gets faulty or breaks, you will start noticing strange noises or difficulty setting the desired temperature in your car.
This can be quite uncomfortable and inconvenient for you and your passengers. This is why you should fix the problem as soon as you notice it.
How to Calibrate Blend Door Actuator
Here are the steps to calibrate a blend door actuator
- Slot the car key in the ignition, move it towards the on, and turn the HVAC system.
- Move the key to the off position.
- Open the hood (bonnet for the RHD guys) and search for fuse #15 in the fuse box beside the battery.
- Bring out of the fuse and wait 1-2 minutes for any capacitive charges in the system to dispel.
- Slot in a new fuse.
- Move the key to the on position. You will now notice that the motor moves as the system goes through the calibration routine. Please don’t turn it off until the calibration routine is completed. There will also be other activities as the door and fan are calibrated.
Running the calibration routine a couple of times will help restore the system to full functionality.
Initially, you will notice that the door, which is significantly different from the failure point, will successfully shift towards the new, correct position setting.
However, the system has to undergo several cycles to achieve the new position setting.
Check Out this video for more tips on blend door actuator recalibration
Also Read: Blend Door Actuator Replacement (Cost & Steps)
Frequently Asked Questions About Blend Door Actuator
What Happens if the Blend Door Actuator Is Bad?
When your car blend door actuator gets bad, the blend door will no longer be working, and you will find it difficult to adjust or change the temperature intensity. Sometimes, it could get stuck in just one setting or be venting out inconsistent temperatures.
How Much Does It Cost to Fix a Blend Door Actuator?
The cost of a blend door actuator is between $100 – $300, depending on the car’s make and model, excluding labor costs.
What Causes a Blend Door Actuator to Fail?
The blend door actuator is connected to an air control door pivot located on the last drive of the unit. An electric motor rotates a plastic gear set from one side to another; when the plastic gear set becomes fragile and eventually breaks, the actuator will become faulty and fail.
Can You Drive Without a Blend Door Actuator?
You can drive without a blend door actuator because it has nothing to do with the driving systems. However, a bad blend door actuator can cause discomfort to both you and your passengers since it affects the car’s temperature.
How Long Does It Take To Fix a Blend Door Actuator?
It will take about one to two hours to fix and test a blend door actuator.
Can a Bad Blend Door Actuator Drain Battery?
A bad blend door actuator can run down your car battery when the AC stays on for too long.
Why Is My Car Blowing Hot Air on One Side and Cold Air on the Other?
The most common symptom of a bad blend door actuator is that your car will be blowing cold air on one side and hot on the other. This problem can be diagnosed using an advanced scan tool. The blend door actuator should be replaced when this problem surfaces.
What Does an Hvac Blend Door Actuator Do?
An HVAC blend door actuator is an electric motor that works with sensors linked to the climate control system. The actuator receives and gives out that signal when you initiate the temperature dial.
How Do You Reset the Blend Door Actuator on a Ford?
Bring out the fuse of the actuator from the fuse panel located in the driver’s footwell. This is the first thing you need to do. Let the AC system run for a few minutes when you are done with that. Finally, put off the car and insert back the fuse to see if the blend door is working.
What Is the Difference Between a Mode Door Actuator and a Blend Door Actuator?
Blend door handles the rate at which air blows through the heater core; it also controls the temperature, while the mode door controls the vents and the air that comes through it.
Do You Have to Calibrate a Blend Door Actuator?
After replacing an actuator, calibration is necessary. However, if power is removed, it won’t be required anymore. The air conditioning, temperature, and air distribution blend will self-calibrate when power gets restored.
How Many Blend Door Actuators Does My Car Have?
Most cars have up to two blend door actuators; however, vehicles with the ability to handle temperature at different zones or multiple zone climate control can have more. The actuator operates the activities of the blend door; it can also divert and influence airflows.
What Controls the Blend Door Actuator?
The actuator controls the blend door, which also diverts and influences airflow. Some plastic gears manage them; they move the blend door when the actuator sends the correct signals. The blend door is a flat-panel plastic; that is why it is called a door.
Blend door actuators are unpopular car parts; they are often not discussed because they do not affect the driving system.
However, they can affect your driving experience if they malfunction. You can’t see them until you open your car dashboard, and you barely notice them because they often work perfectly.
As long as there are no manufacturing shortfalls, the blend door actuators will last for a long time.
This means they don’t require regular replacement or maintenance, saving you money and time.
Scott Greene is a seasoned automotive technician for over 5 years and has been deep into advanced automotive diagnostics for a couple of years. He Loveswriting about Automotive Diagnostics and Repair, Trouble codes, Buyer guides for various car parts and accessories, and lots more.
The blend door actuator is a small electric motor in your car that controls your car's climate control system. It looks like a small plastic box with a few plastic gears on the inside. It is so small that you could easily fit it in one hand if you were attempting to remove it.What happens when blend door actuator fails? ›
A faulty actuator can cause the blend door to be stuck in one position or another, resulting in an outlet temperature that's hotter or colder than the desired setting.Where is the blend door actuator located? ›
Most vehicles have two blend door actuators usually located behind the dashboard on the climate control case, one on the driver's side and one on the passenger side.What is the function of a blend door? ›
The blend door actuators, also called HVAC actuators, control the position of the vents that control the flow of air into your vehicle's passenger area. When the blend door actuators are not working properly, this can result in the heating or the air conditioning failing to enter the passenger area.How do I reset my blend door actuator? ›
To reset a blend door actuator, you must remove the actuator, turn on maximum heat on the climate control. Turn the blend door shaft until maximum heat comes from the vents, then reinstall the actuator. Finally, turn on the air conditioner and test the blend door actuators before putting everything back together.Can you manually turn a blend door actuator? ›
Yes, you can unplug the blend door actuator and still have your heater and AC work. The actuator is responsible for opening and closing the door that allows hot or cold air into the cabin. If it's unplugged, the default position is for the cold air to come in.How do I test my blend door actuator? ›
To test the blend door actuator, disconnect your vehicle's negative terminals. If your vehicle has radio code, ensure you write it down, or better still, you might perform a calibration. You might decide to take your vehicle to a mechanic garage if you don't have a calibration machine.What is the difference between blend door and blend door actuator? ›
The blend door can open and close at various positions to block or allow air passing through the heater core in order to achieve the desired temperature inside of the vehicle. The blend door actuator is typically located closer to the heater core and evaporator than the mode door.How much does it cost to fix a blend door actuator? ›
The average cost for HVAC blend door actuator replacement is between $326 and $377. Labor costs are estimated between $195 and $245 while parts are priced at $131. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.How long does it take to fix a blend door actuator? ›
It will take about an hour or two to replace a blend door actuator, including testing it.
- Step 1: Access the Actuator Assembly. ...
- Step 2: Align the Actuator's Output Shaft Gears. ...
- Step 3: Disconnect the Power. ...
- Step 4: Start the Car. ...
- Step 5: Tuen on the AC. ...
- Step 6: Calibrate the Blend Door Actuator. ...
- After You Install a New Actuator.
Mode Door Actuators: The mode door actuator controls what vents have air flow, i.e. floor, panel or front, defrost, or any combination of those.What does an actuator do in a car? ›
Actuators work behind the scenes in vehicles to convert energy into a physical action or force. They perform a variety of performance and convenience functions, from controlling the throttle to directing airflow in the climate control system, and operating power seats and liftgates.Does the blend door actuator control hot and cold? ›
A blend door actuator is a small motorized device used to control the movement of the blend doors in a car's heating, ventilation, and air conditioning (HVAC) system. The actuator is responsible for opening and closing the doors that regulate the flow of hot and cold air into the cabin.Where is the actuator located? ›
The AC actuator is located above or below the coil. It can be set to either single speed or variable speed. When it is not working properly, your AC will be ineffective, and your power bills can skyrocket.How do you calibrate an actuator? ›
Calibration & Troubleshooting WEM Electric Actuator - YouTubeHow do I reset my climate control module? ›
- Turn off your air conditioning system using the thermostat. ...
- Search for the breaker box. ...
- Shut off your AC unit at the breaker. ...
- Wait at least a full minute before switching the breaker back to the “on” position.
- Wait for 30 minutes before turning your unit back on at the thermostat.
This clicking noise is the result of a failed door actuator; more specifically, it is because the teeth on the plastic gear inside have sheared and are now slipping. Nearly all of these failures have been traced back to using an aftermarket door actuator in the vehicle.What happens when an actuator goes out? ›
The most common symptom of the A/C Actuator going bad or when the Blend Door is stuck is when you feel inconsistent air flow coming in. The desired air you want whether it be hot or cold, is being diverted incorrectly, so you are not getting a consistent temperature out of the A/C system.Is blend door open or closed for heat? ›
If replacing a blend door actuator, check to make sure the blend door position is completely closed before installing the new blend door actuator. If the blend door is left open, even slightly, the temperature inside the vehicle will not match the A/C temperature selected.
A grinding or clicking noise often accompanies this, as the parts of the blend door scrape against one another. The noise–which can sound like someone knocking on your door–often begins or is the most noticeable right when you turn the heating/cooling system on.
To test a linear actuator's current draw, simply connect a multimeter in series with one of the leads of a powered linear actuator, and watch the amperage reading as you extend/retract the rod. Based on the reading, you can determine a power supply that will be able to handle that current draw.How much is an actuator in a car? ›
The average car actuator replacement cost is $300, depending, of course, upon your car's make and model. In most cases, a mechanic will remove the malfunctioning actuator and replace it with a functioning one.Why is my car AC cold on one side? ›
Due to the design of dual AC systems, low refrigerant is the leading cause of drastic temperature difference from one side of the dash to the other. Even well experienced car mechanics may be surprised to learn that as little as 4 to 8 ounces undercharged of 134A can make such a huge difference.Is the blend door & mode door the same? ›
blend door controls the temp by moving a door allowing more or less air to blow through the heater core. mode door controls which vents the air blows through.Can I drive without a blend door actuator? ›
Safety: Can I drive without doing an HVAC Blend Door Actuator Replacement. Driving isn't a problem for this environmental issue, but your passengers won't be comfortable or happy. Don't let them suffer, count on a mobile mechanic from Wrench.How many actuators are there in a car? ›
Typically, vehicles have 3 or 4 actuators. Vehicles with rear controlled HVAC will often have additional actuators to control the auxiliary unit, bringing the total per vehicle to as many as 6. DID YOU KNOW?How long does it take to replace door actuator? ›
It takes about 1.5 hours to replace a power door actuator on most vehicles.Why does my air only works on defrost? ›
Bad Mode Door Actuator
The first cause of AC only blows through defrost vents issue is a faulty door actuator. The function of the mode door actuator is to control the vents to ensure that air will be blown out properly according to the custom settings.
GMC YUKON - HVAC SIMPLE RESET - YouTube
HOW TO TEST HEATER AC BLEND DOOR ACTUATOR on Most CarsIs mode door actuator and blend door actuator the same? ›
The blend door actuator is typically located closer to the heater core and evaporator than the mode door. Mode Door Actuator: The mode door actuator controls which vent(s) air blows through. The door on this actuator has two positions: closed and open. actuator is a clicking noise when the A/C system is on.How many actuators does the air conditioning have? ›
4 Types of Actuators in HVAC (Damper & Valve)Why is my defrost not blowing air from vents? ›
If you can hear the blower motor but no air comes from the vents, check the fresh air intake. If it's plugged, clean it. If it isn't, the blend door may be stuck, or the vents may be plugged internally. Check for power at the blower motor.What causes actuators to fail? ›
Normally, failure is caused by application errors, such as side loading, incorrect wiring, poor mounting fixity, excessive loading, and exceeding duty cycle.How much does an AC actuator cost? ›
The average cost for HVAC air door actuator replacement is between $418 and $475. Labor costs are estimated between $217 and $274 while parts are priced at $201. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.What is actuator in HVAC system? ›
Actuators are the interface between the control system and the mechanical system and are critical to accurate control. Typically, 80% or more of direct digital control (DDC) outputs in the HVAC portion of the system go to actuators.How does a heating actuator work? ›
An actuator is the part of the heating system that is responsible for moving or controlling it. It requires a control signal and source of energy (usually an electric current). The actuator responds to the control signal by converting the energy into mechanical motion.How much does it cost to fix a blend door actuator? ›
The average cost for HVAC blend door actuator replacement is between $326 and $377. Labor costs are estimated between $195 and $245 while parts are priced at $131. This range does not include taxes and fees, and does not factor in your specific vehicle or unique location. Related repairs may also be needed.How do I test my blend door actuator? ›
To test the blend door actuator, disconnect your vehicle's negative terminals. If your vehicle has radio code, ensure you write it down, or better still, you might perform a calibration. You might decide to take your vehicle to a mechanic garage if you don't have a calibration machine.
Mode Door Actuators: The mode door actuator controls what vents have air flow, i.e. floor, panel or front, defrost, or any combination of those.Is blend door open or closed for heat? ›
If replacing a blend door actuator, check to make sure the blend door position is completely closed before installing the new blend door actuator. If the blend door is left open, even slightly, the temperature inside the vehicle will not match the A/C temperature selected.Can I drive without a blend door actuator? ›
Safety: Can I drive without doing an HVAC Blend Door Actuator Replacement. Driving isn't a problem for this environmental issue, but your passengers won't be comfortable or happy. Don't let them suffer, count on a mobile mechanic from Wrench.Do blend door actuators need to be calibrated? ›
Do Blend Door Actuators Need to Be Calibrated? It is necessary to calibrate a blend door actuator after changing it but not required when the power is taken out. When you take power out of the system, the temperature, air distribution, and air conditioning blend doors calibrate themselves when the power comes back.How many actuators are there in a car? ›
Typically, vehicles have 3 or 4 actuators. Vehicles with rear controlled HVAC will often have additional actuators to control the auxiliary unit, bringing the total per vehicle to as many as 6. DID YOU KNOW?What controls the blend door? ›
Blend Door Actuator:
The blend door actuator is controlled by the vehicle's climate controls. The blend door can open and close at various positions to block or allow air passing through the heater core in order to achieve the desired temperature inside of the vehicle.
One of the most common signs of a blend door problem is when the defrost is turned on, but it takes a while to get going. Most of the time, the windshield won't defrost, does so slowly, or remains foggy after a while.How do I test my actuator? ›
To test a linear actuator's current draw, simply connect a multimeter in series with one of the leads of a powered linear actuator, and watch the amperage reading as you extend/retract the rod. Based on the reading, you can determine a power supply that will be able to handle that current draw.Why does blend door actuator click? ›
This clicking noise is the result of a failed door actuator; more specifically, it is because the teeth on the plastic gear inside have sheared and are now slipping. Nearly all of these failures have been traced back to using an aftermarket door actuator in the vehicle.Where is the actuator located? ›
The AC actuator is located above or below the coil. It can be set to either single speed or variable speed. When it is not working properly, your AC will be ineffective, and your power bills can skyrocket.
An actuator is a device that produces a motion by converting energy and signals going into the system. The motion it produces can be either rotary or linear. An actuator is a device that produces a motion by converting energy and signals going into the system. The motion it produces can be either rotary or linear.How long does it take to replace a blend door actuator? ›
Replacing the blend door actuator is actually a fairly simple process, and it should take no more than an hour. So the labor will cost you around $75 – $150 depending on labor rates at your local repair shop.Does the blend door actuator control hot and cold? ›
A blend door actuator is a small motorized device used to control the movement of the blend doors in a car's heating, ventilation, and air conditioning (HVAC) system. The actuator is responsible for opening and closing the doors that regulate the flow of hot and cold air into the cabin.What is a heater actuator? ›
Most late-model cars use electric motors (called actuators) to change the air temperature and direction of the airflow by opening and closing flaps in the heater box under the dash.