I wanted to post this to help any other Caravan owners with their rear A/C units only blowing hot air. The reason is one of the actuators (blend door) is no longer working properly. The part was about $50 from Dodge. This was the 3rd year in a row that this part failed on me. Now that my van is out of warranty, I didn't feel like paying $500+ to have the dealer do this repair for me.

Steps to repair:
1) Start by taking the rear, right inside panels off. There are a couple of screws and small panels but the rest is held on by the standard compression fittings. The whole side will have to be lifted and held out of the way as the rear seat belt is strung through the panel and can't be removed.

2) From underneath the rear passenger side, directly behind the rear tire and beside the muffler is a couple of heating lines and a 13mm nut in the middle. Remove this nut so the blower unit can be released from above.

3) From the inside, remove the upper plastic air pipe and the lower air pipe that directs the air flow. You can now see the hard A/C lines with a couple of flexible pipes in the middle, held to the side by a hard plastic piece. Remove the bolt holding this piece and the two bolts holding the rear blower unit to the side of the van. The whole blower unit can now be laid on its side with the rear of the unit facing up (gently).

4) The actuators can now be replaced. If you are only replacing the blend door, it is the lower unit. The upper unit controls the air flow to the floor or roof outlets. The actuators are held in by two screws each.

​​​​​​I original saw an article saying that I had to remove all the coolant but after performing the repair, if you're gentle enough you should not need to do this as the flexible pipes allow for the A/C lines to be manipulated without damaging the lines.

Hope this helps. Let me know if I need to add more detail.

This the the blower unit with the floor direction plastic piping removed to reveal the A/C lines. You notice the black area that are the flexible pieces.

 

Thanks for the great post, but I have one slight correction, the pipes you can see in your picture are the heater pipes, the A/C lines run out the bottom the unit and through the floor behind the wheel well.

 

Im not mechanically inclined so 2 week ago i took my 2012 dodge caravan to the dealer to have the rear blend door replace because it was only blowing hot air in the back. Now today i noticed that the ac wasnt blowing cold air so i took it back and now they tell me the rear evac core needs to be replace. Could they have damage the evac core 2 weeks ago? And not just that they want to add the fact that according to them the nut under the car into the ac line is corroded so they would have to replace the ac lines too. It just seems like a bad coincidence that 2 weeks after they repaired something near the evac core now it is bad. Thanks in advance.

 

This was a great post and very helpful. I attempted to fix mine last night (with success!) and had a couple of additions for your instructions to help out the next guy.

Tools needed: 10 and 13 mm sockets, 13/16" or 21 mm socket, LONG socket extension (12-15"), philips screw driver, small assorted Torx (star) drivers, panel prying tools

Steps to repair:
1) Start by taking the rear right inside panels off by doing the following: The panel above the pass side rear cupholders pulls off and remove 2) philips screws. There is a torx head screw holing in the cargo tie down, and another philips head hiding behind a round rubber plug on the panel at the top of the hatch opening. Remove the lower seatbelt tether by sliding the cover up and lossening the 13/16 nut. Once you have all those out, pull the 2) plastic compression plugs close to the rear pass window, loosen the rubber hatch seal, and take the bottom hatch panel and the upper rear column pass panel completely off. Next the large panel can be loosened starting at the back and working forward. I loosened it without removing it and propped it open to access. The whole side can be removed but will need to be lifted and held out of the way as the rear seat belt is strung through the panel and can't be removed.

2) Jack up the rear pass side to access the rear wheelwell. From underneath the rear passenger side, directly behind the rear tire and beside the muffler is a couple of A/C lines and a 13mm nut in the middle. Using the long extension, remove this nut so the blower unit can be loosened from above.

3) From the inside, remove the upper plastic air pipe and the lower air pipe that directs the air flow. You can now see the hard coolant lines (deliver heat so they may be HOT) with a couple of flexible pipes in the middle, held to the side by a hard plastic piece. Remove the 10mm bolt holding this piece and the two 10mm bolts holding the rear blower unit to the side of the van. The whole blower unit can now be GENTLY lifted slightly and tilted on its side with the fender side of the unit accessable.

4) The 2) actuators can now be accessed and/or replaced. If you are only replacing the blend door, it is the lower unit. The upper unit controls the air flow to the floor or roof outlets. The actuators are held in by two Torx screws each, DON'T DROP THEM!

5) Now it gets tricky: CALIBRATION. The new actuator needs to be "calibrated" or simply have it's splined post turned to a usable position electronically as it will turn much further than the flaps they mount to will allow. The actuators turn almost 270 degrees but the blend door only turns about 90 degrees. With the actuator unhooked, gently push the actuator into it's desired location by twisting the whole actuator until the spline line up. It will more than likely be askew to its correct mounting position, but you only need to get it in far enough that your can twist the whole actuator to see the range of the blend door's movement. Get it close to the middle and mentally or physically note where the open tooth on the spline needs to be in order to use it. Now, you will need take it out, hook it up to the plug, rest it loose where you can see it twist and start the van. I had my daughter help with then next step by moving the temp dial all the way left (cold) and noting on the actuator where it stopped turning. I then did the same for right (hot) and noted that. Remembering where you need it to be to "plug in" to the blend door, you can now manipulate the actuator to where you need it to twist to by using the temp control. There will be some trial and error involved but I promise you that it can be done. After you get it close to where it needs to be to be installed, go ahead and mount it and put the mounting screws back in. Always check its operation before reinstalling the assembly to the van.

6) Reinstall the assembly and recheck that it is operating correctly. Then reinstall the panels by reversing the order of removal, and take care that nothing is binding or pinched. The panels are kind of a pain but take it slow and work from one side to the other and note if there are joints that are toothed to fit together. After they are all installed, push the rear hatch seal tight to the ridge it sits on and push the panels' edges into gap they are supposed to fit into. Finally remove the jack and do a last check that everything is still working and that all screws and parts and accounted for.

​​​​​​I original saw an article saying that I had to remove all the coolant but after performing the repair, if you're gentle enough you should not need to do this as the flexible pipes allow for the A/C lines to be manipulated without damaging the lines.




Added Notations

 

Reviving an older, but awesome thread here because I just replaced the rear, lower blend door and all was quiet for about three weeks, then I replaced an alternator (disconnected the battery) and now the blend door is clicking.
On install, it slid right in. During install, I disconnected the battery, installed the door, then it operated as it should, however the rear defrost would blink 50% of the time on start-ups, and the AC would hesitate to come on while the light was blinking. I was hoping this would work itself out & go away.
Fast forward three weeks, my alternator needs replaced, so I did, and now my rear blend door is making a huge racket with this awful clicking noise after opening the door, and at other times it chooses to. I can force it to click if I turn the temperature dial ALL the way hot, and now it's starting to do it ALL the way cold.
Any advice?

 

South Main Auto Repair has a couple of videos on Youtube where he replace the blend door actuators and one where he replaces the rear evaporator on DGC.

There's no need to remove the nut that hold rear evaporator expansion valve it could cause some refrigerant to leak out which is environmentally unsafe plus it could introduce humidity into the system which could be detrimental in an A/C system.

In the video where he replace the blend door actuator there's enough movement after unbolting the rear unit to change out the blend doors actuators with precaution and due diligence,

 

Correct!!! My mistake. Now that I've had to replace my whole lineset to the rear unit ($1500 CND), I've learned the A/C connection is underneath the rear corner RIGHT BEHIND THE WHEEL! This connect is exposed to the elements and WILL fail.

 

 

Yikes!
I removed the nut and had it removed for at least five minutes. I wiggled the unit after loosening the nut and noticed no extra wiggle room, so I re-tightened the nut. Thankfully, I didn't hear any hissing sounds. Maybe, 7 years of road junk & corrosion kept everything together as I played with the evaporator.

 

UPDATE: I installed a new rear blend door, and the defrost light still blinks on start-up. Is there any way besides going to the dealer to get this calibration to complete itself? Pull a fuse, put it back in? etc?
BTW, the clicking is gone, and the clicking from the 3 week old unit didn't show any damage--meaning, I pulled the blend door motor apart and all the gears & teeth looked okay. They must have some flex and skip under high tension, making all that racket.