AC Blowing Hot at Times

I own 2002 V6 Off Road manual with 164k on the clock. AC will blow cold, then suddenly blow hot. If I move temp to red (hot) then back to blue (cold), it will blow cold again. Could this be the blender door?

 

On the newer trucks with electronic hvac there is a lil deal under the dash i believe on the passenger side. Its a black box with a white arm that wigs out causing that symptom. Its fairly common to happen, ive read about it a few times, never owned one with electronic hvac though. Some guys can manipulate that arm by hand to temporarily fix/troubleshoot the issue. Its there to see if ya just look up under there, dont have to dismantle anything. Hopefully so.e of the guys that have delt with this first hand will come along and help ya out more...

 

Just out of curiosity, when it blows hot have you noticed if the AC light goes off on the button? Before my compressor seized up a couple times I would notice the ac was blowing warm air, and when I looked at my light I had noticed it wasn't on.