Blend door actuator number and location(s)?

Yes there is one for each side. If you have the option to split the front temperatures they work independently, if you don't have that option they work together. The left one is behind the dash on the HVAC case above the throttle peddle. You remove the lower trim panel and look up and the actuator is bolted to the case. The passenger side is the same but on the other side of the HVAC case.

Thank you. I can reach up and feel the driver's side actuator moving, but the heater does not blow heat on the driver's side, only on the passenger side. I couldn't reach up and find the the passenger side actuator. My next step is to flush the heater core, and if that doesn't fix it, I'm not sure what to do next.

There are two actuators on the drivers side, one is for the mode (floor, dash defrost) the other is temperature. If you switch the mode control does the air move with it? If yes but you feel no temperature change I would find an inspection camera and snake it into the system and watch to see if the temp door moves as you change the temp. That will show you if it is working. I've seen more than one actuator that moved but didn't move the door because of a tab or notch broken.

Are there more than one blend door actuators in a 2008 kia sorento, one for passenger, one for driver?

Yep, here are the locations of the blend door actuators, I will also send you an email. For the passengers side blend door actuator you will need to remove the glove box and the lower panel on the passengers side. Check out the images (below). Let us know if you need anything else.

Hey, thanks a whole lot, Ken! Do you have any idea what the part number would be for the passenger side actuator would be?

If you don't have heat on the drivers side it wouldn't be the passenger side actuator. However the Kia part number is 971542G000 That covers both sides as well as the mode actuator, the only one different is the recirculate door.