Hello all. I have a 2009 1500 with manual thermostat controls. About 2 months ago I started getting the knocking behind the dash indicating that the blend door actuator needed replacing. I replaced it and all was good for a day or 2 and then it started up again; however, it was worse than before and then the heat went out. I replaced the first blend door actuator and the second one for the heat and still getting the horrid knocking sounds behind the dash and my heat and AC are intermittent. I have been quoted at $1200 to replace the box and actuators etc....but I don't want to spend $1200 if I don't have to. What could be the issue?

 

there is a calibration that needs to be done to the SW in the truck after you replace the actuators. Basically, when you installed the actuators, the software doesn't know what position they are in. It may think the last position is cold and you installed the actuators with the door in the hot position.

 

Pedro Dog, where can I find out how to calibrate it?

 

mine went out , thank goodness for the maxcare warranty

 

The dealer has to do it. Mine went out and they installed the actuators under warranty and then did the calibration. I think that they command the actuators to the different positions and sense when they hit the stops by sensing the motors current draw. They then set the controls so they don't keep driving the actuators (motors) after the stops so they don't strip the plastic gears.

Maybe you can replace the actuators and have the dealer do the programming soon after.

 

Thank you sir. I will see how much the dealership costs to have it done. They tend to price gouge you here in Utah, but if there isn't any other option then I will have to look into it. Thank you.

 

I took it to the dealership and it wouldn't calibrate. Should I replace the actuators again and take it in to have it recalibrated or does it need the whole evaporator box replaced?

 

This was a TSB I believe, but not a recall. I remember having mine done on my 2010 TRX.
Luckily, it was covered.

 

when you replaced the actuators did you try to rotate the gears to verify that the doors moved freely? If they are not stuck, I think good actuators with the calibration procedure should work.