AC/Heat problem

I have a 2007 PI and recently lost heat and ac. All the controls do what they are supposed to do but both heat and ac blow room temp only. Fuses and relays are all good. Is this a blend door actuator problem? This is my guess and I'm basing the next question on a yes answer. Is it possible to access the actuator by making an eightXfour hole in the top of the dash above the radio. I would prefer not to have to pull the dash out of the way since everything else works good.

Yes, sounds like the blend door actuator.