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.