I'm curious about this as well, but going the opposite direction

 

I think I've read something about this before and from what I remember it was a giant pita

 

Definitely not a plug and play as the HVAC box behind the controller is different as well.

 

Assuming the electronics and the actuator works, I would save the effort and just replace the blend doors with this or a similar kit:
http://www.ebay.com/itm/Automatic-T...9-04-Jeep-Grand-Cherokee-/282364395878?fits=Model:Grand+Cherokee&epid=570752767

Essentially, you remove the glove box and cut a hole into the bleed door channel with a dreml. Then take out the broken plastic crap and put this in instead. Then put the cut-out piece back in and secure it with duct tape, and re-fit the glove box.

And Viola, the driver's side controls now controls both sides. It took me less than an hour to do 10 years ago and still works like a charm.

 

It'll be about a thousand times easier just to do the blend door fix (which is permanent if you use the metal doors) than to try and swap dual-zone to single-zone.

If you're pulling the HVAC box anyway, then the blend door fix will be insanely easy, with no Dremelling needed.

 

I found also some information about it some months ago but nothing concrete. Now I found some guys that can do it and next month I will change it. Find more here if you want the same thing.

This is getting confusing when you say you can't change a dual-control over to a single-control HVAC system. Then you say you found some information about changing it over but post a link for finding a career by attending a vocational school??

Don't know why you wouldn't just follow the instructions in the last video I posted which would be a little easier than attending a vocational school. Just my take...

 

Yes, i just performed this conversion myself a couple days ago. I had recently gone in and replaced the blend doors with the kit from JGC. The blend doors were supposed to operate independently of each other(thats why they call it dual zone-I know) but for some reason, my blend doors got seized to each other. My drivers side seemed to switch from heat to A/C fairly well, but my passenger side would not come off heat at all. When i got back inside the HVAC box to see what was going on, i found the issue with the doors being stuck and removed them again to try to remedy the situation. I was unsuccessful at seperating the two doors(dont know what the HELL was sticking them together) I finally gave up and drilled out the backside of the blend door shaft for the passenger actuator so the door could spin on the actuator freely, and put it all back together. I now have heat and A/C like i want, i just ignore the passenger knob and use the drivers side to control temp to both sides. Seems like its gonna work perfect for me. I know they have kits designed to do this very thing, and it seems WAY easier to do than swap out the electronics and add vacuum lines, etc. That's my two cents...

 

Pulling the dash isnt that bad the hardest for me was taking the heater core hoses off the firewall. I actually reused my evaporator and heater core because I couldn't get the oem heater core lol.

 

To the OP's original question - yes, it is possible because just about anything is possible if you throw enough time and money at it. Apparently, not very many people have done it -- maybe no one though I doubt that, because there doesn't seem to be much discussion about it here in the forum. Within the few threads that have popped up over the years, I don't recall ever seeing anyone who claimed to have actually done it. Check that - I think maybe one guy might have about 10 years ago.

Anyway, you'd have to pull the dash, replace the HVAC assembly, plumb, I think, two vacuum lines, possibly add some wiring, etc. It would be quite a project on the advanced end of the scale.

 

Some of these members/posters won't be answering since this is a 3-year old thread which was re-opened.

Below is a video showing the Dorman blend doors being installed by going through the front of the box. This is a dual-control blend door system which is being converted to one door control since Dorman only makes them for single control.

Believe one of our Mods, could have been @Jeeples, did this same fix in converting a dual-control system to single control. I don't see why it would pose any problems.

I decided to keep my 04 dual-control AZC system when I replaced mine from the blendorstore. Only went this route since my wife is cold-blooded! :grin2:

Below is the thread/write-up and you may want to go straight to the photos to avoid the long text.

https://www.jeepforum.com/forum/f310/blend-door-problems-fix-questions-4310749/index2.html#post40249155

 

You can swap dual zone to the single-zone. I am not the best expert in this domain, maybe are people which can swap this but I couldn't do this. I read a lot of sites but none shows how to swap it. I observed that my skills in cars are old and began to find an online school to refresh. If you find more here about how to swap dual-zone, I want to know about it.

 

I have an 04 with the dual zone. It never made a whole lot of sense to me. But it worked ok. I replaced the resistor and it’s harness a year or so ago for the blower motor, pretty much all the air comes out of the driver side. But if I put it on heat it heats the Jeep quickly. If I lower the temperature the air comes out cooler. Other than adding a can of refrigerant every year the ac works as well. I guess doing the blend doors would improve air flow on the passenger side? I guess I have more of a “let sleeping dogs lie” attitude. Like I said both heat and a/c work rather well. One issue we’ve had with the Jeep since buying it, is after shutting down the vehicle, a minute later it sounds like it has some gastro intestinal thing going on. Kinda like it’s farting or something. Last for nearly a minute. Comes from the upper passenger side dash area. Anyone else have this issue?

 

I have an 04 with the dual zone. It never made a whole lot of sense to me. But it worked ok. I replaced the resistor and it's harness a year or so ago for the blower motor, pretty much all the air comes out of the driver side. But if I put it on heat it heats the Jeep quickly. If I lower the temperature the air comes out cooler. Other than adding a can of refrigerant every year the ac works as well. I guess doing the blend doors would improve air flow on the passenger side? I guess I have more of a "let sleeping dogs lie" attitude. Like I said both heat and a/c work rather well. One issue we've had with the Jeep since buying it, is after shutting down the vehicle, a minute later it sounds like it has some gastro intestinal thing going on. Kinda like it's farting or something. Last for nearly a minute. Comes from the upper passenger side dash area. Anyone else have this issue?

Yeah mine did that same sound before I tore it all apart sounded like it I ws coming from the mode door side I had only the recirculation door broken all my actuators were functional but some spun slower then others. I replaced all the doors but 2 with the blendoor doors and the noise is almost gone in fact it sounds just like my 16' longhorn ram does now.

Although I refoamed the hvac box it made little difference to airflow. Mine had a kind of dead spot from 21° to 24° I would have to go up past 24° or down below 21°. It was annoying because travelling at night with a broken recirculation door having the ac blasting cold air with the fan at its lowest without turning it off got chilly. It's nice to be able to set it to 22° now

 

That sound is ... "normal". My '99 with the AZC makes that noise too a short while after shutting it off. I believe it's the result of a broken actuator going through its normal calibration routine which would otherwise be much quieter or even silent if it weren't broken.

 

Yeap, that sounds about right but with 99' Laredo (single zone).

 

If I were you I'd fix the existing system.

 

One issue we've had with the Jeep since buying it, is after shutting down the vehicle, a minute later it sounds like it has some gastro intestinal thing going on. Kinda like it's farting or something. Last for nearly a minute. Comes from the upper passenger side dash area. Anyone else have this issue?[/QUOTE]

I have a 99' Laredo (single zone), and get that similar sound when shutting down that lasts about 10 seconds...It sounds like a Compressor is shutting down (pressure) along with one or more of the Doors closing (farting/gastro sounds).

Joe

 

Hi Bigrigr, looks like I live near you (Pleasant Grove). I have driven a 2000 Laredo 4.7 for the last two years and never had trouble with the heat-A/C. My son now drives it. I recently bought a 2004 Limited 4.7HO and had a bunch of refresh work done. It has dual zone and when the AC us on, I get cool air from the driver/center dash vents (though not great airflow) but warm air is coming from the passenger dash vents. I had the system recharged with new freon (w/dye) in March and see no leaks. I ran the diagnostic but there are no fail codes. I pulled the head unit and applied aluminum tape in case it would increase air flow. And I have ordered the fused-together blend doors to simulate single zone, but am not sure if that will address the problem of warm air coming from the passenger side when calling for A/C. Any advice for me? Thanks!

 

Good to see another Local Jeep junkie on here....

I installed the JGC blend door kit that was supposed to retain the dual zones. It worked while it was cold outside, but when i wanted the A/C to cool it still was not working on the passenger side. I then removed the blend doors and modified them to lock together so that they are now on a single zone setup. Its been working great ever since. I just ignore the right side display and knob, and set my requested temp with the left knob. It is possible to always have cold air from the passenger side, or warm air all the time, depending on where the blend door is stuck at. When you get in there it will all make sense.

 

I'm sure some of you are experts on this issue, but my plot thickened this morning. I planned to install the fused blend doors on my '04 Limited 4.7HO. As soon as I pulled the glove box, I found aluminum tape? Yep, a rare positive surprise from a previous owner who had replaced the blend doors and converted to single zone. They work fine, thankfully. And the recirc door also works just fine. My question or problem remains - I get very little air flow from the passenger side dash vents, and it blows warm air when I'm calling for air conditioning. In other words, the driver side dash vents blow cold while the passenger side dash vents blow warm. Somehow, my wife isn't a fan of that setup. So we usually climb into her 2018 WKII Summit instead. But I want my WJ to work right, so any ideas will be appreciated. Thanks!

 

Are you sure the two doors are locked together? There are several kits out there that restore the dual zone system. This is the kit i initially installed, but i found out later that my rear actuator motor was malfunctioning. Rather than tearing the whole dash out to replace this actuator, I just glued the two separate doors together and turned it into a single zone. Double check your doors to make sure they open and close as one unit.... If they dont, then you need to swap your new kit in

 

Thank you for hanging in there with me on this topic, BigRigr. The blend doors that the prior owner installed are indeed fused, so they always move together. I drove the WJ to my trusted mechanic yesterday. He checked for freon leaks and found none. He evacuated and recharged the system and confirmed that the system had retained 100% of the freon he installed in March, so coolant is not suspect. We confirmed there are no blend/recir door fault codes. He ran the recalibration sequence (pulling the fuse, etc.) and still warm air continues to flow from the pass side dash vents while cold air is flowing from the driver side. He thinks there is another door deeper in the air box that is somehow stuck which is allowing the warm/cold condition from the same zone (dash vents). I haven't seen any comments here about another door. We may have to yank the dash and lay eyes on the whole air box assembly to drill down to the problem (ouch!).

 

That really makes no sense to me. I am no expert obviously, but i have had my blend doors apart a couple different times now. When i first went into my dash to fix the originals, all I got out of the passenger side was cold air(this was in Dec-Jan i think) My originals were crumbling apart, I literally had to suction the pieces out with a shop vac. I installed the new split doors per the instructions, and i had heat again on both sides of the dash. I believe the doors were in the down position to get heat(they naturally rest there I think). I thought all was well, until it started to warm up outside and i started using my A/C, I then only had heat coming from the passenger side vents. I went back in and discovered that something was wrong with my passenger side actuator(its on the backside of the hvac box pinned against the firewall. No way to replace without a complete dash removal) I fused my blend doors together with a good glue, and reinstalled them and have good cold A/C and heat now with just using the left side control knob. I assume that to get A/C the doors are in the up position, and heat is in the down position. If your doors are working correctly, i cant see how you would NOT get the proper air flow?


I do not know of any other doors deeper the system. Only the recirc door and the mode doors. Neither of which effect the temp of the air completely


Not sure i trust the codes in the system on this one. Need to peel back the tape and actually confirm the door function. With the tape removed you can watch the doors cycle while rotating the knobs on the dash.

 

I see you have confirmed the door function earlier, sorry for the mixup. You say you are experiencing low air volume out of the passenger side as well? Maybe the heater core/evaporator is clogged up with lint and dirt? Can you get in behind the tape and try and clean them?

 

Thanks Bigrigr. I decided to bite the bullet. I bought all new everything and will pull the dash and replace it all. While the dash is out, I wanted to install a new heater core but the model for the 2003-04 (with auto heat/AC) is a unique part that Mopar has discontinued. And no aftermarket heater core is available either for the auto heat version. I'll have a radiator shop try to clean my original heater core while it's accessible. And when I put everything back together I'll seal all the ductwork in the hope of improving airflow. This is a costly job, hearkening back to our favorite terms; "J.ust E.mpty E.very P.ocket" and "J.ust E.xpect E.pensive P.arts", right?

 

Oh yeah, this is not a cheap hobby, but it can be fun a rewarding. Based on everything i have read, you should be loving that heat and A/C after you are done. It should mess up your hair when you get it all sealed up!