I found after searching underneath the dash, you can remove the glove box door.. There are two stops on each side near the top, on the sides, you have to pull the sides of the box toward the center , then the box will fall down. Now you can see a flat cover, I think it have 6-8 screws in it, the cover is maybe 8 x 8 inches, pull it off by raising it up the n angle the bottom toward you then down behind the clove box. Inside on the left is the blend door. Try to move it slowly start the truck let the heat go where you want it by moving the door, keep in mind the dial for temperature should be on hot. You can also control the temp with the dial, like halfway , or whatever, I live in Prescott, so I have mine cranked all the way to hot. Now , on the top of the heat box area , up the front of the heater and in line with the hinged part of the blend door on top , just eyeball this and at the very top of the entire box you will see a white part , about 1/2 inch high on the right side of it there is a small 1/4 inch , or so vertical shaft , now only about 3/4" is visual, but its enough to grab it gently with small vise grips and twist back and forth, only do this while you are moving the blend door at the same time, if they move together, the gears on the inside of that white gearbox are good. Ready for round two ??? Now with everything visable and a real good flash light(led) preferred , turn the temp control on your dash one wat of the other, while looking at the blend door confirm that they are , or not working in sequence. Truck must be running. If the dial on the heat temp works ok, but the door does not move, then its time the the thrid , and last round , and a little prayer would'nt hurt either. Back to the white box at the top , and to the small shaft on the right side that is vertical, and kinda in line with the hinged area of the blendd door , from the vertical shaft , go to the left of the shaft maybe an inch to the body , or housing of the white gearbox , about a 1/2" from the right edge take an ice pick and make a hole the same size as the little piece of tubing that comes with almost all rattle can lubricants , and carburetor cleaner, an 1/8" hole should work get a good silicone libricant , attach the little red extension to it and carefully slip the extension into the little hole , and while moving it from left to right, mostly right a little , give it a couple goo shots , and start moving the blend door at the same time as you move the temp control from cold (blue) to hot ,, at this point it would be better to have someone moveing the dash control so you can view the door, and the small vertical shaft at the same time.. Good luck , mine is still a little sticky ,but it does work now,, Scott