Hello All,
Installed new rear blend door and my 2012 GC likes to blink the rear defrost on start-up & various other times to calibrate the blend door actuator, so I've read on-line. My question is, why does it do this over and over again. Is it because I am a dummy and haven't taken it to a qualified person with the right piece of tech/software to program the actuator? Does this van need to go to the dealer, or is there something that I can do?
Thank you.

 

Disconnect the negative battery cable for about 10 minutes, then hook it back up and turn the key to on/run without starting. That should trigger self calibration, then Let it sit for about 1 minute to let it complete. Cycle the key back to off before starting it.

If that doesn’t do it then you’ll have to take it to a shop (doesn’t have to be dealer) to at least have the DTC’s in the HVAC module read.

 

Did you replace your rear blend door actuator with a Mopar OEM actuator or an aftermarket one I've read when replace with an OEM actuator no re-calibration is needed while with aftermarket actuators their travel is greater so they need to be calibrated. Any service shop that does automotive A/C repair has the scan tool to program these actuators.

 

The door determines travel, not the actuator. While it may be true that aftermarket actuators have greater travel than OEM (which I’m not going to waste time trying to verify), the door will stop the actuator from traveling too far in either direction as long as nothing is broken or preventing normal travel. The HVAC module is capable of reading the travel regardless of whether or not it’s an OEM or aftermarket actuator.

That said, all Dodge service info I’ve ever read in regards to this his will state to perform a calibration after an actuator has been replaced.

 

The door doesn't determines nothing whatsoever it's not a smart device the only thing you need to assure yourself about the door is that it's not broken, The input is signal is sent from the A/C control module to the actuators which open or closes depending on the command received by the actuators. Each individual actuator have a built in potentiometer that send feedback signal to the controller ( A/C module ) that how the controller can determine the position of each actuators. The OEM actuators all have the same operational characteristic so the controller can't differentiate from one OEM actuator from another OEM actuator the only thing you need to know is what is the controller is calling for the actuator spline is keyed so it can only be installed one way. Then before buttoning up you check the operation of your newly installed actuator which should be exactly the same as the other one. No re-calibration needed

The aftermarket blend door actuators from the different companies which produces for many of the different car manufacturer their internal parts are likely all the same for the different car brands with a greater range of travel for the different brands so their operating characteristic won't be same. Their feedback signal value which may not coincide with the controller's input causing the controller to go in a default mode. The only way to fix this is the re-calibration of the actuator with a scan tool so the controller can recognize the feedback signal and determine the position of the actuator.

Dodge service info they also say to always bring back you vehicle to the dealership for any kind service.needed.

 

Wow. That google really serves you well. It’s a good thing everything on the internet is true and unfallible in every way.

Maybe if you bothered to actually learn how these systems are designed to work you might understand what I’m talking about when I say the door is what determines travel. If you can’t figure it out, maybe you should stop spending 10 minutes on google for everything you post and pretend to pass it off like you know what you’re talking about.

 

I don't need the internet to know how an A/C system works I spent most of my electrical career dealing with heating and cooling controls. An automotive A/C system is no different than a DDC controlled building just on smaller scale same components needed for the system to work. Technology changed drastically over the years and it's obvious that you're absolutely clueless about them . PLC and DDC controllers have input and out devices that communicate with each other the automotive industry has now adopted this method of control with blend doors and actuator rather than old in line valve method previously used.

FYI Your famous disconnecting the battery for your fix all solution don't work on the newer vehicles because they have more advance ECM that won't erase itself like in the older model ECM previously used. That the reason why when your bring a car to a shop with trouble the first thing the technician does is grab a scan tool instead of disconnecting the battery. Maybe if you wasted less time disconnecting your battery and educate yourself and broaden your knowledge you might be able to contribute with some practical advice. May I suggest installing a battery cutout switch for your vehicle so instead of always disconnecting your battery you'll just flip the switch and see if that fixes anything for you.

 

Oh gee, thanks for the advice.

I might bother explaining to you why you don’t know what you’re saying but all you ever want to do is argue about how your electrical experience makes you right.

What would I know anyhow? I’m just an auto technician who deals with these issues every week. But clearly your experience outweighs mine. Never mind that you still don’t see the bigger picture of how the HVAC system actually works because all you’re focused on is half the components.

When you’re actually interested in discussing this instead of arguing about it, feel free to get a hold of me. Until then I don’t have the time or the interest in explaining any details to you.

Also, are you sure you have 40 years experience instead of 1 year experience and 39 years of practice?

 

You might be an auto technician but you're no HVAC expert that's a guarantee. No worries I probably forgot more about HVAC that you'll ever know in your lifetime. I've worked on systems that you've haven't even got the imagination to even think about yet.