[MT-2500]

Originally Posted by thomasedwin

The blend door actuator on this 2001 Tahoe was making the click, click, click noise so I took out the dash and replaced the unit. Before removing the unit I ran the heater to verify that this actuator was making the noise, I could hear and feel the unit making the clicking noise, It was difficult to replace because it's located on top of and behind the heater housing just about under the bottom of the wind shield and there's little room to get your hands and tools in there but I got the old actuator out and the new actuator back in and hooked up. I again ran the heater to check and there was no more clicking noise and I could see that the drive mechanism was opening an closing the blend door. I then put the dash and everything back in and then I started it up and let it run for a half hour or so and checked all the heating and cooling functions, everything worked correctly with no problems and no clicking noise. Then about three days later the clicking noise came back and it seemed louder than it was before, I don't know what else to do with it. The replacement actuator was purchased brand new from a reputable parts supply store and I'm 100% sure it's installed correctly. I even checked that the blend door was opening and closing and was not binding and there was no debris or anything blocking the blend door from moving. What could be causing this clicking or causing the new actuator to malfunction like this? I'm thinking of Taking it all back apart and fabricating a cam arm from the old actuator with a cable to manually open and close the blend door but I don't know if disconnecting the wiring will effect some other part of the heating system since I believe it's all controlled by the computer. How can I fix this???????

Did you check the blend door for sticking or binding or broken?