Dual zone climate control conversion...

[HoleshotHolset]

Anyone have a service manual or ever worked on a 3rd Gen to determine how much is really different in the HVAC system between the Laramie with dual-zone compared to a ST/SLT?



If it's only a matter of a new switch and a 'switch plate' then this is something that could benefit a lot of people... .



Even if it cost $400 to do the conversion... it's still cheaper than getting a Laramie... . and paying for all kinds of stuff that you might not want.



Matt

 

[robobx]

I wonder if the temp sensors are already in place for climate control even if we don't have it. That would be the main thing to put a halt to that idea.

But yeah, I would do it in a second for $400 or so. The wife loves to be warm( HOT to me) and I need to be cool when driving long distance.

 

[bighammer]

Intersting thought. I have the Laramie and the service manual so maybe I should check it out. (if I can make the time )

 

[HoleshotHolset]

Do you really think it has temp sensors? I was under the impression that it wasn't all that complicated. Not like a luxury car where both front passengers get a digital readout of temp...



There's a fine line between between a true thermostatically controlled HVAC system, and one that just varies the amount of air blowing past the heater core.



I only want it because it has two zones... I couldn't give a fat rat's butt if it maintains a constant 68ºF in the cab on my side and 75°F on her side... . within an earshot is fine for me.



Good info! Keep it up!!



Matt

 

[RobertBolinger]

From the control it looks like the system in my Grand Caravan-and it does not have sensors-it just has a slider control for each side.

 

[robobx]

ok, my fault. when I read it to be dual zone "climate control" i automatically assumed sensors and a more complicated system. if it's just a duel thermostat system, then we'd just have to worry about a different set up for choosing where the air goes and at what temp. not just the controls. later, I'll look at my service cd and try to see if there is a difference, unless someone beats me to it.

 

[AndyMan]

From what I can tell reading the service manual, you would have to add an additional blend door, and blend door actuator. I have attached that section of the manual for your reference. I have the dual zone and like it very much. There are no temp sensors, it's just two sliders - one passenger temp, and one driver temp. It appears to be do-able and maybe even feasable.



Here's the excerpt:



BLEND DOOR ACTUATOR

DESCRIPTION

The blend door actuators are reversible, 12-volt

Direct Current (DC), servo motors. Models with the

single zone heater and air conditioner system have a

single blend air door, which is controlled by a single

blend door actuator. Models with the optional dual

zone front heater and air conditioner system have

dual blend air doors, which are controlled by two

blend door actuators. The single zone blend door

actuator is located on the driver side end of the heater-

A/C housing unit, close to the dash panel. In the

dual zone system, the same blend door actuator used

for the single zone system becomes the driver side

blend door actuator, and is mechanically connected to

only the driver side blend air door. In the dual zone

system, a second separate blend door actuator is also

located on the top of the heater-A/C housing unit and

is mechanically connected to only the passenger side

blend air door.

The blend door actuators are interchangeable with

each other, as well as with the actuators for the

mode door and the recirculation air door. Each actuator

is contained within an identical black molded

plastic housing with an integral wire connector

receptacle. Two integral mounting tabs allow the

actuator to be secured with two screws to the heater-

A/C unit housing. Each actuator also has an identical

output shaft with splines that connects it to the linkage

that drives the proper blend air door. The blend

door actuators do not require mechanical indexing to

the blend door linkage, as they are electronically calibrated

by the heater-A/C control module. The blend

door actuators cannot be adjusted or repaired and, if

damaged or faulty, they must be replaced.

 

[HoleshotHolset]

"It appears to be do-able and maybe even feasable."

It can be done! Boo-yeah!



This part of it scares me: "The blend door actuators do not require mechanical indexing to the blend door linkage, as they are electronically calibrated by the heater-A/C control module. The blend door actuators cannot be adjusted or repaired and, if damaged or faulty, they must be replaced. "



I wonder if the heater-A/C control module is any different?



I need to get one of those CD's... sounds like it's jam packed with info I could use to cut corners (and probably end up spending a lot of money trying to reverse engineer things... haha). Got a CD burner?! :-laf



Matt

 

[HoleshotHolset]

Whoa nelly!



I got about 5 people in less than a few hours that were willing to help me out with the repair CD. I have one anonymous TDR member that was willing to put their CD up on a web server so that I could download it. If I have difficulty downloading the CD, I will take one of you up on your offer.



Thanks for all the offers!



I'm positive I can make this conversion work, but gotta do the math and so forth.



Matt - beyond grateful for the overwhelming response!

 

[David Muench]

If you figure it out, post the details. I'd love the dual climate control in my SLT. I wonder if it requires any computer reprogramming. .

 

[lawdog]

Me Too, ... ..... The wife has that in her Durango and I like it there, But I also did not want the Laramie to get in in my Ram...

 

[HoleshotHolset]

I'll write a dissertation on it. Not to worry!



Matt

 

[Shooter]

One of the locals bought the Laramie just for the dual heat/ ac. He hates it. She has herside so hot that the whole cab is an oven and his cool air has to blow directly on him, just cooling his front. If he turns the blower up then her side just heats the cab up more.



Be careful what you wish for.

The heater core has no problem overriding the ac evaporater.



Just my $. 02

 

[HoleshotHolset]

Shooter: Thanks for your input... it definitely is a different side to the story that nobody has mentioned... .



Matt

 

[RobertBolinger]

While that is true, we really like ours (on our Caravan), and rarely have it split that much. If she was that much colder natured than me, I would insist she wore warmer clothes.



If that fails, and it is winter, a drivers side window competely down will override the heater core



If it's summer, an auxillary manual underhood heater control valve only cracked open would keep the heat output in check!

 

[HoleshotHolset]

Robert: I agree...



On my drive from Massachusetts to Wisconsin back in late October... my girlfriend had a blanket and a sweatshirt on for the whole ride. I was in a t-shirt...



I told her well in advance that I would be keeping it nice and cold and that she should dress appropriately... . The driver *should* get preference for radio stations and climate on long drives like that... . especially since she slept 75% of the journey.



I'm still going to research this project... .



Matt

 

[MO'Donnell]

I got the laramie with the dual zone because she likes it a lot warmer than I do. So far it's worked out well, except for the one time she had it SO much warmer that I was concerned a thunderstorm was going to develop!

 

[HoleshotHolset]

I have developed similar weather systems in both the VW and the Dodge... . amongst many other vehicles... . but it never had anything to do with the HVAC system. :-laf



Matt

 

[HoleshotHolset]

Here's a pic of the dual zone HVAC control panel... just in case nobody has seen it:

 

[RobertBolinger]

Did you find out the price of that piece and the extra mixing door-they will probably be the most expensive parts of the conversion. That control panel looks $$.