Blend Doors

[JBDive]

So I keep going over and over my heat problems and really don't feel the heater core is the actual problem. I have always got far to much outside air in the vehicle when the A/C is on recirculate and suspect this is also causing my heat problem now, to much cold air in the mix.

On the 02 it is my understanding you cannot "fix" the positioning of the blend doors by using the heat selector knob and going back and forth three times each, it must be set using some sort of diag tool that Jeep techs have. Is this correct? What is the tool and does it actually provide the info on door position?

Yes I hear the doors open and close and generally it all works as expected other than I can smell outside air when on A/C recirculating and when temps are below 30 outside I have trouble heating up the inside (granted it certainly use to heat better).

 

[Chuck_yager]

I'd be interested in what you find out too. I have an '03 that can get plenty warm sitting and idling, but goes barely lukewarm if you start driving. If I stop and let it sit and idle, especially if I turn the blower down for a bit, it gets warm again. I really don't want to replace the heater core to rule that out since its such a pain to do and I can get really warm air out of it sitting at an idle.

 

[Bulldog485]

I replaced my temp control blend door actuator on my 2012 Jeep Liberty Arctic (KK Model). It was an easy task to get to and the entire job took less than 10 minutes. Whomever had the Jeep before me used a dorman actuator, which is a total piece of crap. I went to Jeep and purchased the OEM Mopar unit and side by side, there is a difference with the OEM feeling beefier. Once installed, I hooked up a Mac Tools MDT-10 scan tool and went into the HVAC system and used the scan tool to run a actuator alignment procedure so this failure should not happen again. You don't need a OEM Jeep Chrysler scan tool to do the alignment but you should use some scan tool that can do the alignment procedure. I'm not sure if you can do it manually as I could not find a reference to it online, but since I have access to this $5000 unit, I figured that I would use it. Hopefully this new one will not fail like the dorman unit did.

 

[TimberWolf]

Where did you get instructions on how to do yours? I've got 2011. Are the pretty much the same. I am having the same problem. I do have a scan tool, but how do I know if i can calibrate the actuator using it?

 

[Bulldog485]

Where did you get instructions on how to do yours? I've got 2011. Are the pretty much the same. I am having the same problem. I do have a scan tool, but how do I know if i can calibrate the actuator using it?

I just looked everything over and pulled the actuator, picked up a new one and verified that the blend door works and used the Mac Tools MDT-10 Scan Tool to do the recalibration of the actuator motor.