When A/C is on, front blows cold air but rear blows hot air through lower vents.

I suspected that. I'm in the process of pulling the rear quarter trim panel now ! Well I pulled the actuator, hooked the wires up to it, layed it on top of the a/c unit where I could see it from the front, started the motor and turned on the a/c and it rotated. Turned off the a/c and switched it to heat and it rotated the other way. Cycled it several times and it operated both directions every time. I reinstalled it and tried it. It would not move the blend air door ! Seems like the actuator motor is too weak to operate under load ???