Where is the Mode door actuator located?

Hi Steve W. Thank you so much for the information. I removed the fuse that you indicated and allowed a minute to pass before putting the fuse back in and turning the car on, however, that did not resolve the issue. Yesterday (before reading your post) I pulled part of the dash out and I was able to see the mode door actuator and was able to observe it moving when changing the vent settings from defrost vents, front vents, and floor vents. The actuator would move when you select any vent setting except for the front vents. I then manually moved the door (the piece that is attached to the actuator) to the bottom, and then air was coming out of the front vents. I then changed the knob, so air goes to the floor, and it did, then changed it to defrost and it did change. I repeated the process a couple of times trying different settings to see if the actuator would move when the setting was on the front vents. The actuator moved to the front vents a couple of times then it did not anymore, but it continues to move to the other vents when prompted, I had to manually move it in order for it to move to the front vents. I am not sure if there is something that is making the door get stuck when it tries to move to the bottom (allowing air to come from the front vents) or if there is an electrical or other mechanical issue.

In your previous response, you mentioned that the control head might be the problem, would you mind telling me what the control head is, where to find it, and if you still suspect it as the problem?

If the problem is with the actuator itself and I am able to pull it out without removing all of the other parts, would it be advisable to do so or is draining the coolant and removing the console necessary parts of the process?

I was also trying to find the actuator at AutoZone or Advanced Auto but for some reason, no one has this part, do I need to buy it directly from GM, and if you happen to have the part number, I would appreciate it too.
Thank you again so much for your time and expertise.

I was able to take the actuator out and the plastic part that sits on the actuator. The plastic piece has groves in it in which there are three white pins that sit in the groove and move as the actuator and plastic part move. These pins move along the groves and control where the air is coming from. When I took the actuator out (it took a couple of hours without pulling the entire dash out) I cleaned the grooves as there was crusted grease which I believe was causing the binding and I added more grease into the grooves to help the pins move freely. I put the actuator back (which took a lot of time and I needed the help of another person, I had to take the radio out, so the other person is able to place the pins in the correct place while making sure the screw holes were in the correct place). Now everything is working perfectly. Just for reference and if anyone is wondering how to do it without pulling the dash, the way I was positioned was very awkward. I had to put the driver's seat all the way back, my feet were on top of the seat where the head is usually there, my head was near the brake pedal, and I was inverted on my back. If anyone knows of another way to do this job, I would very appreciate it.