Air blend door actuator stuck making clicking under the dash.

If the bolts are from the blend door assembly, the blend door actuator could easily dislodge and jam. You will need to get in behind the dash and inspect the door actuator function. The actuator is new and shouldn't have failed already, so you might be able to salvage it and regain proper operation.

There is blend door in vent channels under the dash of the vehicle. It blends warm and cool air in the vents depending on the temperature setting. The Blend Door is controlled by a motor called an actuator that gets its signals from the setting on the dash. When the actuator fails the blend door can't move. If it stops on hot you always get hot air.
3 possibilitys
1. Blend Door stuck.
2. Temperature control not sending signal to actuator.
3. Actuator motor gone bad.

Of the 3 possibilities the actuator motor is the most common and the easiest to fix. The part is $40-90. I don't know exactly where actuator is on the Pilot. My GMC you remove the plastic trim below the dash and its just to the left of the glove box near the 'hump'. Perhaps the part store can tell you or someone else will offer the exact location.

Once you remove the actuator you can plug it back in to the wire clip and move the temperature knob and see if it moves. When you get the new one plug it in and make sure it turns before bolting it in.

To clarify a bit. The heater is never technically turned off. The blend door determines how much it goes thru the vents.

Yes the fix is to remove the dash from the car and replace the blend door and the blend door actuator.

Air Temperature Control Blend Door Failure No Heat or no AC (dependes on where door sticks)

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.

Other causes of no heat in the cabin are engine thermostats that are stuck open (engine runs cold) or air bubbles in the cooling system.

I know this post is old but for those of you experiencing this clicking noise it appears from my research so far that it is the actuator that moves the blend door. A couple of people even repaired the motor assembly because it appears to slip where the motor drive connects to the worm gear. If you search sienna ac actuator you can find the videos, I belive one guy was named Froggy. My passenger is stuck on cold and the driver side makes noise when moving to cold, the driver side also seems to hesitate going to warm. It's $120 for a replacement actuator. I'm really close to changing it, you just have to make sure the door and motor arm Match positions for it to work right. The dealer seems hesitant to replace it since they are worried it may be loose foam in the blender box. The box costs $3500 to replace though since its buried in the dash, and from what I've seen researching this the actuator is a possible issue in multiple models as well as Lexus vehicles and some other brands.

The most likely cause is a failed blend door actuator; however I recommend a little troubleshooting. First, can you hear a clicking sound behind the dash when you turn the setting to hot? If yes, it is certainly the actuator stripping its gears. If not, check to make sure the heater hoses are both hot as they connect to the heater core at the firewall (in the engine compartment). If one or both of the hoses do not get hot, there is a blockage caused either by an air bubble or a stuck water control valve in the heater hose. If the hoses are both hot, the indication is again the blend door actuator.

Below are instructions for replacing the actuator. Look at the diagrams carefully--the big arrows point to the front of the truck and the actuator is on the side of the heater box above the outlet duct that runs to the driver's side of the floor. Also, the actuator is expensive, so I recommend you make sure it's bad and shop around a bit to get a good price. To check out the actuator, first see if you can turn the blend door by hand. If you can't turn it, maybe it's jammed. Also, reconnect the actuator after removing it and see what it does when you turn the heater to hot.

Removal & Installation

1. Remove the floor air outlet duct extension (1) from the floor duct (2).
   

   

Fig. Remove the floor air outlet duct extension (1) from the floor duct (2)

Disconnect the electrical connection at the blend door actuator (#10 in pic below).

Fig. Blend door actuator and related components

Remove the blend door actuator mounting screws from the HVAC module.

Remove the blend door actuator as an assembly with the actuator cam.

Fig. Remove the blend door actuator mounting screws from the HVAC module

To install:

1. Install the blend door actuator as an assembly with the actuator cam.
   1. Line up the heater/defroster valve lever with the blend door actuator cam slot.
   2. Line up the A/C valve lever with the blend door actuator cam
   
   
2. Install the blend door actuator mounting screw to the HVAC module.
   1. Tighten the blend door actuator mounting screw to 14 inch lbs. (1.6 Nm).
   
   
3. Connect the electrical connection at the blend door actuator (10).
4. Install the floor air outlet duct extension (1) to the floor air duct (2).

Picture of actuator:

Blowing hot air when set to A/C is almost always a stuck blend door, dead blend door actuator, or a cracked or disconnected blend door actuator vacuum line. The blend door is inside the a/c ducting under the dash, but the actuator will be accessible outside the ducting.

Blend air door may be stuck. I removed a pencil from a heater box before. It had fallen from the dash, down through the defrost vents and jamed the door.

there is a blend door actuator for the laredo and if is bad the air wont come out here is a pic of what it looks like and how to get to it


The single zone heater-A/C system is equipped with a single blend door actuator. The dual zone system has two blend door actuators, one for the driver side blend-air door and one for the passenger side blend-air door.

1. Disconnect and isolate the negative battery cable.
   
2. Remove the glove box from the instrument panel.
3. Remove the three screws that secure the blend door actuator to the passenger side of the HVAC air distribution housing .
4. Remove the blend door actuator from the air distribution housing and disconnect the HVAC wire harness connector from the actuator.
5. Remove the blend door actuator from the vehicle

to instal

1. Position the blend door actuator into the vehicle.
2. Install the blend door actuator onto the passenger side of the HVAC air distribution housing . If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those on the blend door cam .
3. Install the screws that secure the blend door actuator to the passenger side of the air distribution housing . Tighten the screws to 17 inch lbs. (2 Nm).
4. Connect the HVAC wire harness connector to the blend door actuator.
5. Install the glove box into the instrument panel.
6. Reconnect the negative battery cable.

I ended up taking the vehicle to the dealer. The 'blend door' actuator had gone bad (stripped gear?). $66.00 for the part over $330 for labor. The console and part of the dash had to come out.