Where does vacuum go to, to operate blend door

This is the climate control default mode. You most likely have a problem with an electric/vacuum operated blend door motor under the dash attached to the heater box assembly. Some diagnostics will be required to determine which actuator is problamatic and whether or not it is a vacuum/electrical issue or a problem with the actuator/door itself

here's a few things (1) is the thermostat facing the right way /the arrow head facing out towards the front of the car or facing up towards the hood ? the blend door actuator/the a/c vacuum control valve/ or vacuum lines can be broken connected wrong or missing altogether here's some pictures for you
this is a blend door actuator

I don't know which one you have or both

a/c vacuum control valve

this is the blower motor resistor I really don't think so on this one because the fan blower works ,so concentrate on vacuum lines and the vacuum controls here and you should be warm soon good luck

Go directly towards a vacuum leak . The vacuum reservoir is notorious for going bad in the these vans , unfortunately you have to pull the heater box to repair it which takes numerous hours. Hopefully it is just a vacuum leak that's accessible. If its a diesel I would first check the vacuum pump , if its gas then start by checking the small vacuum line under the hood along the cowl on the right rear of the engine compartment. Pull apart one of the tee fittings and check for vacuum with the engine running . Then check inside the truck pass side under dash for a bunch of vacuum hoses . Got vacuum?

The blend door is probably what is keeping the air from blowing across the heater core and picking up the heat. I hope your manual gives a description and procedure for it.

The blend door actuator and other heater case doors will be either vacuum operated with a few canister diaphragms situated around the heater case, or they may be operated with electric motors. If you pull off the lower sound insulator panels below the dash, you can see the bottom of the heater case, and then find the actuator for the blend door. If vacuum operated, check for vacuum. The vacuum for the heater/AC controls comes from a single line from the engine, through the firewall, and into the back of the control head or to a control module. Then, many vacuum lines branch out from this central point to the canisters- the heater/AC controls will direct vacuum to appropriate actuators, or servos.

It can be a jamming door has damaged the actuator motor, both problems are common on this truck. You can buy a kit on line that is called a "HEATERTREATER" THAT ALLOWS YOU TO REPLACE THE BLEND DOOR WITHOUT REMOVING THE DASH, EBAY ALSO HAS THE KITS.

olandchavaz, What you need to do is check in the engine compartment for a vacuum line coming through the firewall. This engine vacuum is what controls the actuators. A small piece of rubber hose will correct the problem should you find a broken line. Good luck with this.l

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:

The blend door is not working right or the in car air temperature sensor is faulty.
Removal & Installation Air Inlet Door Vacuum Motor To Remove:

1. Remove the instrument panel.
2. Remove the air inlet door motor mounting screws. CAUTION
   Do not attempt to bend any part of the air inlet duct door lever.
   
3. Rotate and remove the air inlet door vacuum control motor.

To Install:

1. Rotate and install the air inlet door vacuum control motor.
2. Install and tighten the mounting screws.
3. Install the instrument panel.

Defroster Door Vacuum Motor To Remove:

1. Remove the passenger air bag module from the instrument panel.
2. Disconnect the vacuum line and remove the mounting screws. CAUTION
   Do not attempt to bend any part of the defroster airflow mode door lever.
   
3. Rotate and remove the vacuum control motor from the defrost door lever.

To Install:

1. Rotate and install the vacuum control motor on the defrost door lever.
2. Install and tighten the mounting screws.
3. Connect the vacuum line to the vacuum control motor.
4. Install the passenger's air bag module.

Floor Console Register Duct Vacuum Motor To Remove:

1. Remove the floor console.
2. Remove the right-side instrument panel insulator.
3. Working from the passenger's footwell, disconnect the vacuum hose.
4. Remove the screws and the floor console register duct vacuum control motor. CAUTION
   Do not attempt to bend any part of the floor console register duct door lever.
   
5. Rotate and remove the vacuum control motor from the floor console register duct door.

To Install:

1. Rotate and install the vacuum control motor on the floor console register duct door.
2. Install and tighten the mounting screws.
3. Connect the vacuum hose to the floor console register duct vacuum control motor.
4. Install the insulator under the dash.
5. Install the floor console.

Panel/Floor Door Vacuum Motor To Remove:

1. Working through the driver footwell, remove the two screws and the shield. CAUTION
   Do not attempt to bend any part of the airflow mode door lever.
   
2. Label and disconnect the two vacuum hoses.
3. Remove the mounting screw.
4. Lift, rotate and remove the panel/floor door vacuum control motor from the door lever.

To Install:

1. Install the panel/floor door vacuum control motor on the door lever.
2. Install and tighten the mounting screw.
3. Connect the vacuum hoses in their original positions.
4. Install the shield on the vacuum motor.

Auxiliary Air Distribution Blend Door Actuator To Remove:

1. Remove the right rear quarter trim panel access panel. Auxiliary climate control housing removal and installation
   
   
2. Remove the auxiliary air distribution blend door actuator screws.
3. Disconnect the auxiliary air distribution blend door actuator connector.

To Install:

1. Connect the auxiliary air distribution blend door actuator connector.
2. Install the auxiliary air distribution blend door actuator screws.
3. Install the right rear quarter trim panel access panel.

Auxiliary Temperature Blend Door Actuator To Remove:

1. Remove the right rear quarter trim panel. Auxiliary climate control housing removal and installation
   
   
2. Disconnect the temperature auxiliary temperature blend door actuator connector.
3. Remove the temperature auxiliary temperature blend door actuator screws.
4. Remove the temperature auxiliary temperature blend door actuator.

To Install:

1. Install the temperature auxiliary temperature blend door actuator.
2. Install the temperature auxiliary temperature blend door actuator screws.
3. Connect the temperature auxiliary temperature blend door actuator connector.
4. Install the right rear quarter trim panel.

--- In-Car Temperature Sensor Removal & Installation To Remove:

1. Remove the instrument cluster finish panel.
2. Disconnect the in-vehicle temperature sensor connector.
3. Disconnect the in-vehicle temperature sensor aspirator tube.
4. Remove the in-vehicle temperature sensor screws.
5. Remove the in-vehicle temperature sensor.

To Install:

1. Install the in-vehicle temperature sensor.
2. Install the in-vehicle temperature sensor screws.
3. Connect the in-vehicle temperature sensor aspirator tube.
4. Connect the in-vehicle temperature sensor connector.
5. Install the instrument cluster finish panel.

sounds like the air intake up under the glovebox blend door is stuck or the actuator is not moving the actuator uses the engines vacuum to operate u might have a vacuum leak ... get under the dash on passenger side and look for this actuator then move it in and out to see if its **** it might work if u loosen it up if its not stuck pull the rubber hose off actuator and see if it has suction if not you have a vacuum leak or a blockage in that hose good luck chris wojcik maryland

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.