Can dual zone HVAC be replaced with single zone? - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 28 Old 08-11-2017, 06:33 PM Thread Starter
Grant Miller
Registered User
2002 WJ 
 
Join Date: Oct 2007
Location: Kansas City
Posts: 75
Garage
Can dual zone HVAC be replaced with single zone?

On my '02 Overland, I will be pulling the HVAC box for repairs. I've got access to a complete Laredo and wonder if I could swap out the dual zone HVAC for the single zone. I know that the dual is electronic and the single is vacuum, but are there major issues to deal with? Or is it just a matter of getting all of the parts switched over? Has anyone done this?


WJ's are a lot of work!
Grant Miller is offline  
Sponsored Links
Advertisement
 
post #2 of 28 Old 08-11-2017, 06:42 PM
RightIsRay
Registered User
2000 WJ 
 
Join Date: Mar 2016
Posts: 17
Garage
I'm curious about this as well, but going the opposite direction
RightIsRay is offline  
post #3 of 28 Old 08-12-2017, 02:03 PM
Jeep318
Registered User
2002 WJ 
 
Join Date: Nov 2012
Location: Medford
Posts: 355
I think I've read something about this before and from what I remember it was a giant pita
Jeep318 is offline  
 
post #4 of 28 Old 08-12-2017, 04:11 PM
Montreal300
Registered User
 
Montreal300's Avatar
1999 WJ 
 
Join Date: Jan 2015
Location: Cornwall
Posts: 954
Definitely not a plug and play as the HVAC box behind the controller is different as well.

1999 Jeep Grand Cherokee, Laredo (White) with 4.0 137,000 miles.
Montreal300 is offline  
post #5 of 28 Old 08-15-2017, 04:07 PM
GC002
Registered User
2002 WJ 
 
Join Date: Jul 2011
Location: Portland
Posts: 17
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-Te...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.
GC002 is offline  
post #6 of 28 Old 08-15-2017, 04:44 PM
AVR2
Web Wheeler
2002 WJ 
 
Join Date: Apr 2007
Location: UK
Posts: 4,410
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.
AVR2 is offline  
post #7 of 28 Old 04-09-2020, 07:52 AM
Bigrigr
Registered User
 
Bigrigr's Avatar
2000 WJ 
 
Join Date: Jan 2020
Location: Near SLC
Posts: 994
Garage
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...

'00LMTD-4.7l,242hd,D30,D44A,3.73's,True-trac front,Spartan rear,4" short arm lift,JK'sW/32's
Bigrigr is offline  
post #8 of 28 Old 04-09-2020, 08:59 AM
xcaliber81
Registered User
 
xcaliber81's Avatar
2004 WJ 
 
Join Date: Jul 2012
Location: Prince George
Posts: 4,992
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.
xcaliber81 is offline  
post #9 of 28 Old 04-09-2020, 10:03 AM
99wjtx
Registered User
 
99wjtx's Avatar
2001 WJ 
 
Join Date: Aug 2017
Posts: 640
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.

Rage! Rage against the dying of the Jeep.

99 WJ Limited 4.7/NV247
01 WJ Laredo 4.7/NP242
99wjtx is offline  
post #10 of 28 Old 04-09-2020, 10:51 PM
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
2004 WJ 
 
Join Date: Jan 2012
Location: Central
Posts: 10,277
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!

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...l#post40249155

2004 4.7L WJ Limited, 96 4.0 ZJ


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Uniblurb is offline  
post #11 of 28 Old 04-10-2020, 02:12 AM
Rhanks11
Registered User
 
Join Date: Apr 2020
Posts: 6
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.
Rhanks11 is offline  
post #12 of 28 Old 04-10-2020, 03:15 AM
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
2004 WJ 
 
Join Date: Jan 2012
Location: Central
Posts: 10,277
Quote:
Originally Posted by Sebastrue View Post
You cannot swap dual zone to the single-zone. If you change it, you will make a big mistake.
Quote:
Originally Posted by Sebastrue View Post
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...

2004 4.7L WJ Limited, 96 4.0 ZJ


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Uniblurb is offline  
post #13 of 28 Old 04-10-2020, 08:08 AM
Spyder62
Registered User
 
Spyder62's Avatar
 
Join Date: Sep 2019
Posts: 189
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?
Spyder62 is offline  
post #14 of 28 Old 04-10-2020, 09:04 AM
99wjtx
Registered User
 
99wjtx's Avatar
2001 WJ 
 
Join Date: Aug 2017
Posts: 640
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.

Rage! Rage against the dying of the Jeep.

99 WJ Limited 4.7/NV247
01 WJ Laredo 4.7/NP242
99wjtx is offline  
post #15 of 28 Old 04-10-2020, 09:22 AM
xcaliber81
Registered User
 
xcaliber81's Avatar
2004 WJ 
 
Join Date: Jul 2012
Location: Prince George
Posts: 4,992
Quote:
Originally Posted by Spyder62 View Post
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
xcaliber81 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome