The temperature control on this truck is actuated via a cable. The blend air door, which the cable moves, controls the temp entering the vehicle.
Because of the year, I don't have any specifics as far as pics, but I have done enough of them to walk you through it.
The first thing you need to remove is the trim panel that goes around the radio, HVAC control unit, speedo and so on. There are several (allen type) bolts holding it in place. Remove them and carefully remove the trim cover.
Next, there should be (2 or 3) screws that hold the HVAC control unit in place. Remove the screws and gently pull the unit outward. Note that the cable and wiring will not allow you to fully remove the unit. However, once it is about 1/2 way out, you should be able to see the cable and where it attaches.
Check to see if it is attached, if something is broken and so on. If it appears to be good, disconnect it from the unit and manually try to move the cable in and out to see if you hear the blend air door opening and closing.
I was able to find two pics. The first one (hard to see) shows location of the blend air door. The second shows the lever which the cable attaches to.
Let me know what you find or if you have other questions.
Images (Click to enlarge)
Saturday, September 26th, 2020 AT 5:52 PM