Defrost Only, No Vents or Floor. 2011 DuraStar

The main connector to the control head should have good power at A1(A73A) and A2(A75D), ground is at B6(A74-G). You should have 12 volts to the actuator while it is suppose to be moving. From the control head wires in cavity B9 and B10 go to the mode door actuator which is wire #A74 and A74A, both light green colour wires. Make sure you have good continuity on both to the actuator. The part number for control head I see is 3545543C. There is calibration procedure, but it is easy, all you have to do is unplug the control head for 30 seconds. It will self calibrate once you key back on.

 

I went back as far as 2004. The control head uses the same connector and the wires are pinned the same, so I would say if you found one from an older unit it should work just fine.

 

I have a similar issue my different modes doesn't work just stuck in defrost once I key on it will go from the floor to the vents then back to defrost I took the cold hot actuator which is working and connected it the the mode actuator connector ... Nothing

I replace the blower temp mode module on the dash still the same thing blower settings fine cold hot fine still no changes on the mode side but when I put either actuator in the mode connector I can feel the actuator take some type of power on each turn on the dash control but the circle doesn't turn on the actuator

Any advice will help

 

Try your testing again, every time you disconnect something and reconnect, you need to reset the system by performing a key cycle.

 

How do you reset system

 

Key on, key off, wait 15 seconds or so, key on.

 

So to make sure I'm right unplug everything key on then key off plug everything back up then key on ... also, forgot to mention I hear a clicking noise where the flap door is similar to like a jam I have the actuator in my hand so it's not connected but when I do key on I can hear the noise as if its trying to move and cant I do have a fault code spn 3984 fmi 2 which I was told hvac motor wrong position another guy hvac control head

 

If the actuator is turning just fine in your hand, then it must be the door/flap mechanism. Those doors and plastic gears are actually pretty good. Never really saw one break. It was always the actuator that was broken. Have a close look at the drive collar or socket of the actuator itself. Usually they split and will slip around the mating drive collar of the door mechanism.