Where is the driver side blend door actuator on a 98 Seville STS?

Videos and text based articles. They are nearly always to the left and right of the centre console under the dash.

https://www.google.com/search?q=1994+cadillac+seville+sts+replace+blend+door+actuator

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Assuming the blend doors are not moving at all, can the blend doors be moved manually? If so, on the electrically controlled actuators, make sure they are in maximum or minimum position such that the electric positioning sensors are showing maximum or close to zero resistance before starting the car - this can be really important for the HVAC module to reset the position feedback of each properly.
You may also have a problem with the wiring connectors on the HVAC control module. They should be coded so they will only fit in the correct sockets, but the pins may not be seating properly - you can try checking the pins on each and then reinserting the connectors firmly.
If there are pneumatic actuators, check the vacuum at each -if none in all HVAC positions, there is probably a problem with the vacuum or HVAC control modules.
Bottom line - the most common problem is a bad or wrong HVAC control module.

I would pull off the blend door actuator and swap it out with a new one. Or another option is to swap it out with one of the other actuators. The blend door actuator is interchangeable with the actuators for the mode-air doors and the recirculation-air door.

Disconnect and isolate the negative battery cable.

If equipped, remove the silencer from below the driver side of the instrument panel.

Disconnect the wire harness connector from the blend door actuator located on the driver side of the air distribution housing.

Remove the two screws that secure the blend door actuator to the actuator mounting bracket and remove the actuator

many cars automatically kick on the air compressor in defrost, to dehumidify the cabin air

probably blend door on driver side stuck or bad actuator

I am trying to locate the ac blend door actuator on my 2000 cadillac seville sts: AC blows air on the floor only instead of the dash board ac vents. Appreciate any help

Its your blend/actuator door. Its behind the dash and controls whether heat or a/c get through when your fan is on or anytime for that matter.

I'm having the same problem except on mine it's the driver's side that's blowing cold. Do you have the pictures in a finer resolution? I can't make them out and when I zoom, they are too grainy. Does the replacement require removing the dashboard? What's the general cost of the acuators? Are they readily available at like NAPA or other parts stores?

Same problem on my 98 Regal GS; remove glove box, locate the blend door actuator, (black odd shaped box with metal "ring"). Remove the box and manually turn the blend door shaft it was attached to. If you get cold air, it's the actuator you removed. About 30-40 dollars.

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.