As Duranged point out, there is a flapper door in the rear that routes the air through the A/C or heater core depending on the selection. Try your A/C and see if you can get cold air back there. if so, sounds like your flapper is either stuck or broken and not making the switch.
Either way you will probably end up pulling the passenger side rear interior panel to make the fix.
2004 Durango SLT AWD 5.7 Hemi Flame Red with 3.55's
2004 Ford Crown Victoria Sport 4.6L Midnite Gray with 3L27's
2011 Hyundai Santa Fe GLS AWD V6 Mineral Gray (Hers)
I'll throw my hat in being a victim of this problem as well. I have a 2001, 4.7, bought with 40K on it, and now has 70K on it. As far as I remember, I've never had working heat back there. I did try to get into the rear panel where all of the equipment is, but I can't figure out how the get the panels out of there without messing with the 3rd row seat.
I got some of the panel pulled back, but not off enough to inspect all of the equipment that is mounted up in there. Any tips/thoughts on getting in there to check it all out?
I bought it used from Usa (live in Sweden) in november 2007. Change it to Km right after I got it, so I only know thi kilometers milage... 89000km.
It works fine everything (fan) but I wont get any warm/hot air out of it... The problem is just in the backseat, in front it works as it should.
You can control it from both front or back passengerseat.
I thougth that it hould be like that (little suspicious)likethe hot airshould be mixed with cold to get an good effect !??
The Swede from the country "Farfaraway" just got a Durango R/T
After working on it today, I discovered a few things that pertain to my version of the problem. The servo that operates the flapper door is working perfectly fine, but the stop tab on the outer sheath that connects the servo to the flapper arm mechanism had snapped off at some point, which let the servo continue to spin, which then must have overpowered the flapper's arm and snapped that as well. As a result, the flapper was just sitting inside laying over top of the heater core.
I was able to pull the flapper door out of the unit to at least let some air hit the heater core, but since the air is not forced through the core, the air doesn't really even get warm.
I wasn't able to get the unit fully disassembled to assess whether or not it would be feasible to replace the sheath and the flapper door since they are both broken, but at least I know exactly what is wrong and what needs to be replaced (assuming I can find the parts and get the rest of the unit disassembled).
Thats great to hear Dango, not every time would finding a problem be that easy. I apologize for not being able to help you out on the dissasemby. Im stuck in the 90's with my rear air being blown from the front...
The entire system back there is pretty straightforward and it's easy to understand the layout and operation. There's just a few bits of patience needed to take the rear inside panels off. Unfortunately, I just could not get the entire front plate off of the HVAC unit itself so I could assess the parts I need to replace and to remove the broken servo-connection-sheath thing.
The entire front plate is on there with at least 15-20 screws, and I still couldn't get it to really budge off - I was only able to pry it open a bit to get the flapper door out. Unfortunately, the numbers etched onto it don't seem to reflect a part number.
Most vehicles don't have rear ventilation controls anyway, but since I have the system back there, I'd like it to operate in the manner in which it was designed.
Perhaps I need to track down an original shop manual for the disassembly and the part numbers so I can price out this repair.
Went to the dealer parts counter today to look for the parts. They still make them. As a matter of fact, they told me that the new '08 Durangos are using the same exact system for the rear heat and a/c. So, the good news is that the replacement parts are available, but only when you buy half of the entire unit, which costs $137. Forget that. I need two parts, not most of the entire unit.
The frustrating thing is that the two parts that I need actually have individual part numbers, but are not available for purchase without the rest of the unit.
After talking to the parts counter the first thing you do is tella salesman you want to take an 08 durango with rear heat out for a test drive. lmao j/k Or am i? I know how that feels to go through that, my luck is i ask for a part, they say its in stock, and when i show upthey tell me i haveto buy the whole unit. Got into an argument with the manager because i had to drive 45 mins for nothing. Although i never did get a response when i mentioned he must have given me the waranteeversion over the phone and now thesales version in person. Low rate used dealerships can get to ya....
OK, here's some resolution to this tale (for me at least).
Since my encounter with the parts department at the dealer, I made a few phone calls to local junk yards. I was able to locate a yard nearby that had two D's to part out. I pulled in around noon and they put the parts (servo, coupling, and door) in my hands in about 15 minutes, and only 25 bucks later.
Came home, installed it, and tada! Heat in the rear system again!
I did make a few observations about these parts however. The servo that controls the door rotates well beyond the half inch or so it takes to switch temperature settings. They stop by the sheer brute force of the little plastic stops that tab out from the coupling and hit other tabs on the exterior of the ventilation housing. Needless to say, the servo still wants to turn and pushes pretty hard on those tabs. Naturally, they will eventually fail.
Also, the servo that was pulled from the yard had a very similar product number, but ended in an "B" instead of and "A" and was made by a different manufacturer. I decided to install the 'new' servo with the 'new' door, as these parts were not broken and came from a working ventilation system (at least before the D ended up in the yard). Perhaps the servos that were installed at the factory in some trucks were slightly different after all and are more likely to damage the components and create this common failure. Who knows, that is only pure speculation.
While this whole project wasn't anything absolutely crucial to the functionality of the truck, it was certainly gratifying to rectify the issue and spend some quality time taking the D apart and putting it back together. At least now I won't have to listen to family and friends complaining of freezing in the back during the winter while I sweat in the front trying to get some heat back to them.
thats great Dango, not only was it a plus for you, but other D owners aswell. I highly doubt you will be the only one that will experience that problem (unless it was me) so now somone has an insight to a possible fix.