Stuck on defrost why?

Then the actuator is not getting power or the control head has gone bad.

Yes, but it will need to be scanned to see if it is that and giving a code. An auto parts scanner will not get these codes so a mechanic needs to do it.

It sounds like the mode actuator is not working but to be sure check out this guide.

https://www.2carpros.com/articles/replace-blend-door-motor

Please run down this guide and report back.

There is a series of doors that control air direction. The doors are operated by and electronic actuator that can be bad or the doors can be jammed. You can usually access the actuator and mechanism from under the dash on the driver;s side.

Welcome to 2CarPros.

Your description sounds like you have either a bad mode cam or the door itself has failed. If you can hear it most likely the actuator itself is working, it just isn't moving the door.
The mode door actuator is on the end of the HVAC unit on the drivers side right above the transmission tunnel. Item 3 in the image. To get to it you remove the floor air duct that blows into the drivers foot well, then look above the outlet for that duct and you will see the actuator and the cams and linkage that move the mode doors for defrost/vent/floor. There is an electrical connector and two screws that secure it. Reach up and change through the modes and see which parts are not moving. The plastic parts get brittle and fail or simply fall apart loose. You can get the complete assembly as shown in the last picture from Rock Auto or a dealer. It includes the cam that tends to break. Sometimes you can glue them back together as well.

That sounds like a bad mode actuator and cam. The mode actuator is on the drivers end of the HVAC case just above the plastic floor duct over your feet. You remove the duct and the actuator is there. Be sure to line up the heater/defroster valve lever with the mode actuator cam slot and to line up the A/C lever with the mode actuator cam. When you install the replacement part. The plastic piece you see on the last picture is the cam. When the motor moves that moves the various doors to send air to the floor, dash, defrost. I have seen them break open and the door pins come loose from the cam.

The mode door actuator will have the cam on it like the last picture.

The blend door controls the temperature of the air by controlling how much goes through the heater core and is a different part in a different spot.

The part you need to look at is # 3 in the first picture. It is very possible the actuator itself is OK but the levers that connect to the cams are unhooked. If you use a light and look up above the drivers foot well you should be able to see it and watch it move.

Try pulling fuse for HVAC inside truck for sixty seconds with key on that resets actuators. The wet floor board can be a plugged drain which is under truck and can be cleaned by using a coat hanger into it to clear it. I am assuming A/C pipe gets cold under hood. The mode controls direction and blend controls temperature. See picture.

Then the mode actuator in picture that I sent earlier is probably bad. It can be reached from drivers side by gas pedal. Also, when you run the A/C feel the large pipe and it should be cool/cold to the touch and maybe dripping water if not then the A/C should be checked for pressure as it may have a leak or low.