If you open the glove box then squeeze the sides in a bit the glove will drop all the way open to the floor . Then with a mirror you can see the right side end of the blend door shaft i t has a two inch long lever on it . This lever contacts a vacuum valve when the blend door is fully open . You can "help " this lever along a little while the actuator motor is clicking to get past the the bad spot of stripped gears to put the blend door in full heat position. The permanent repair is to replace the blend door actuator motor . Available at many places auto zone napa advance for about $45.00 It is fairly easy to replace about 45min to an hour .