Swapping rear HVAC controls - possible?

[cptmoney]

So I have access to the rear hvac controls that look like this:



Can I / should I swap these in place of my "a/c only" controls that are in my Tahoe? What all is involved? If I simply swap out the controls, do I automatically get rear heat? Is the foundation in place to run heat and cool already in place? I'm guessing that's a blend door of some sort, that would allow me to control the temp better than my current "a/c only" setup that I have now. Is that blend door already there? Just needs the right wiring? Or is it much more involved?

Just curious. If it's a simple yank and swap, it would be preferable to have fill temp control for the rear. If it's a huge undertaking, I'm not going to mess with it.

Has anyone done this before? I did a search, but didn't see anything. Curious what's been figured out about all of this....

 

[M1Gunner]

What's your model and year? And what year did those controls come from?

If yours does not have controls for heat then unfortunately no you will not get rear heat. If you look underneath behind your right rear tire you will see two A/C lines. In order to have rear heat you would need the coolant lines that WOULD have been run back there for a heater core for rear heat.

 

[cptmoney]

Here's what I'm seeing under the rear of the "a/c only" Tahoe:

I haven't had the chance to peek under the back end of the model with full rear heat/cooling controls, but I'm betting you're going to tell me that's what those two pinched off lines are in the first image - the heater lines! Haha.

It's not looking like something I want to mess with..... Would be quite the undertaking, I believe.

Am I correct in my assumptions?

 

[M1Gunner]

So I have access to the rear hvac controls that look like this:



Can I / should I swap these in place of my "a/c only" controls that are in my Tahoe? What all is involved? If I simply swap out the controls, do I automatically get rear heat? Is the foundation in place to run heat and cool already in place? I'm guessing that's a blend door of some sort, that would allow me to control the temp better than my current "a/c only" setup that I have now. Is that blend door already there? Just needs the right wiring? Or is it much more involved?

Just curious. If it's a simple yank and swap, it would be preferable to have fill temp control for the rear. If it's a huge undertaking, I'm not going to mess with it.

Has anyone done this before? I did a search, but didn't see anything. Curious what's been figured out about all of this....

Here's what I'm seeing under the rear of the "a/c only" Tahoe:

I haven't had the chance to peek under the back end of the model with full rear heat/cooling controls, but I'm betting you're going to tell me that's what those two pinched off lines are in the first image - the heater lines! Haha.

It's not looking like something I want to mess with..... Would be quite the undertaking, I believe.

Am I correct in my assumptions?

Unfortunately, you're correct that you don't have the coolant lines, only the AC refrigerant lines. That being said, no rear heat. The "pinched" line you're referring to is the drain tube for the rear AC's evaporator. It produces condensation and the water collected drains out of the rear evaporator case through that.

When you get a chance to look under the other Tahoe with rear heat you will see a set up like this


The two bigger lines on the left are the coolant lines that are missing from your setup which would supply the hot engine coolant for the rear heat.

 

[cptmoney]

Ahhh - gotcha!

Thank you very much for your help! That answers a lot of questions for me, all in one shot.

I really appreciate it. Thank you!

 

[M1Gunner]

You got it brother, that's what we're here for! Sorry it wasn't something more in your favor but happy I could help!

 

[cptmoney]

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