AlleninNM

2006 F150 with auto air. Have the issue where temperature is either all hot or all cold. I am aware of TSB 08-23-6 which just calls for replacement of temp blend door actuator. No problems with where the air is going (defrost, floor, vents) Just problem with temperature control. I figured I would take a look to see if I had the foam issue with the vent control doors, so I removed the radio and then removed the front of the HVAC vent systems, as described HERE. No problems with foam falling down and the vent door moves normally.

That allowed me to reach in and access the temperature blend door with my hands. After I have removed the temperature blend door actuator, I can easily move the temperature blend door by hand. But the "throw" of the portion of the temperature blend door that I can reach seems to be about an inch or so. The opening of the temperature blend door itself may be more than an inch, but the portion that I can reach with my hand only moves about an inch. It swings easily and seems to have a solid stop at the extreme end of each direction. So I don't think there is something blocking the door.

When I replaced the temperature blend door actuator, the problem remains. In addition, I now get a loud clicking noise when the temperature is set at its lowest. Just a couple of clicks then it stops. I assume the clicking is just the gear stripping because it cannot turn the blend door as far as it wants to turn it. (The old actuator did the same, but without the loud clicking. It may have just been so worn out it did not have the ability to make the clicking noise.

So my questions is, has anyone ever checked the temperature blend door itself, and how much "throw" did it have? Has anyone had issues of this type that were NOT fixed by replacing the temperature blend door actuator?

EDIT: While moving the blend door by hand, and feeling where the actuator would move the door, it appears the actuator would not need to move more than 1/4 turn to go from full left to full right. Anyone know if it should be moving more than this?

FURTHER EDIT: I attached the actuator and turned on the HVAC. If I adjust the temperature between 65 and 73, I can feel the blend door move in small increments. Anything above 73, and it feels like it is just tightening the door, but the door is not actually moving. If I take it below 65, which just takes it all the way to 60, then the door moves more than just an incremental amount and the actuator tries to move the door beyond its limits, which then causes the clicking noise. Is there some sort of controller that tells the actuator how far to move?

650NutKase

The blend door actuator uses the contacts its PCB to know where to stop. There are sweeping contacts on that board that tell it where to stop. I dont think you have an issue with your doors. What brand of actuator did you use in the replacement. I've gone through 2 dorman units in the last 5 months, so it may be the actuator itself that is bad.

AlleninNM

The replacement was a Dorman. Since it sounded worse than the factory actuator, I pulled it out, repositioned the factory actuator and put the original back in. Ran out of time and buttoned it all back up.

Since putting it back together, I have not really tested it, but it seems to be working OK using auto temp controls. I will try it out using manual and see if it works.

gilmour68

I just replaced mine and I'm experiencing the same issues with clicking on both ends of the temp scale...2008 F-150 XLT 5.4

I had used the gear from the original part to rotate the door and align the key so I could install the new actuator. When I fully pressed the old gear into the socket, I was able to lift the door/socket probably 1/8" so I'm wondering if something is worn or misaligned since there seems to be considerable vertical play. I haven't located a diagram showing the internal workings of the door assembly, so I'm not sure what might be going on in there.

I had some trouble getting the shaft of the new actuator to engage more than 50% with the socket on the door, possibly because of the sag in the door assembly. Eventually I had to wrap a bit of tape into the grooves of the actuator to ensure the fit was secure. The door seems to rotate freely approximately 90 degrees back and forth and I feel a solid thump on one end of the rotation.

The new actuator turns the blend door, but I can't seem to get it to calibrate - it clicks slightly at full cold and begins clicking at about 3 o'clock on the heat side. I tried removing fuse 13, then fuse 15 and turning on the ignition to perform a recalibration, but the clicking remains. Is it possible something is obstructing part of the rotation on the heat side? If so how can I access the door to remove any obstructions I might find? I believe there might be something preventing the door from the full heat position, I have reasonable heat in the cab, but it's not as hot as it should be.

Thank you for any help!!! BTW I replaced the original unit (123K miles) with a Dorman.

Unrealrussell

My blend door actuator was on the fritz, I changed it but it would switch to fresh air after I put it on recirculation but not all the time, was intermittent i changed out HVAC climate control head unit, i have manual control with *****, I bought used on Ebay, fixed my problem. 2006 Ford F150 FX4 5.4L
Dont bother with aftermarket, more headache than it's worth, Motorcraft parts, spend the extra so you dont have to change it twice, my experience from fan clutch, blend door actuators, cop,....

650NutKase

It very well could be a defective Dorman part. They are known to make terrible actuators. I had to do the job 3 times because of defective parts that wore out after a month or so. Motorcraft is the way to go. If you suspect a blend door issue that is NOT linked to the actuator, you basically have to remove the entire dash to gain access to the doors.