Hello and welcome to JustAnswer!
The blend door actuator is on the bottom of the heater box on the right side, the actuator itself can be accessed from inside the passenger compartment on the right side. If you hear the actuator moving but temperature doesn't change then most likely the blend door is broken. What you can do is remove the actuator and inspect it and the area of the door that it engages, and you can also try moving the door by hand.
If you find the door won't turn by hand or the drive area of the door will turn a full 360 degrees without stopping then the heater box will need to be removed and disassembled to get to the door, and yes this does require removal of the instrument panel.
I had a quick look and it appears the noise of the motor or actuator is coming from the driver side up to the left. The white plastic wheel that appears to control the vents works OK but to the top left it has a motor that keeps running for a short period. Is there a diagram of the a/c anywhere that I can use to point it out?
Right Hand drive. The Blend door I think is stuck closed as the climate control only blows cold air. If I turn up the temp the door motor / actuator just keeps running trying to let hot air in.