I actually pulled the valve control motor out and took it apart. It's a mechanical failure within the motor assembly. The clicking or grinding noise comes from a worn pinion on the shaft of the motor turning against the teeth of a cog.

If you hear this noise, there is a good chance that this motor will eventually fail as the pinion gets jammed against the cog when it is actuated all the way. The motor simply doesn't have the torque to unjam itself.

It is such a simple device: a 12V DC motor, 3 pastic gears and a plastic actuator arm. That's it.

See my reply at http://www.mitsubishi-forums.com/index.php...otor+valve+dash

Yep, I have the same thing at about 80k miles. I had a clicking noise when I'd go back and forth with the heat control. Well, now the noise stopped and so did the heat. i'm stuck on cold and I'm freezing. I just began my research on what the problem can be and after reading your post, looks like i now know.

I guess I have to go to a mechanic, doesn't sound like i can do it myself.