3rd gen 3500, replaced blend air door. Now when you turn switch to blow out main vents it goes to floor, when you go to defrost it goes to main vents and if you keep moving the switch it goes to defrost. Not sure if I need to take it in to have it factory reset or if the control panel is the problem!

 

Unsure but there are 5 blend doors on my 04 4wd ram 1500 , I had to pull dash and change all of them , no trouble since but yours may have some differences , you might check and make sure the actuator is hooked up properly but there is more than one blend door and actuators , or fittings on the actuator could be bad striped busted ,,not saying its not another electronic control issue but the doors an actuators are notorious for breaking