99 Yukon wants rear heat-has rear a/c now

[OR VietVet]

I have been working on a 1999 Yukon 4 door, where I fixed a coolant leak problem and he is aware he likely has a blend door/actuator problem because he does not have good heat at the vents. See my work info on this truck in the Garage section.

He has rear a/c but wants to add rear heat. He does have the overhead rear a/c control up front and he said there is just one knob control in the rear area.

Is there a kit or way to add rear heat to this vehicle? Any info/help is greatly appreciated.

 

[Eman85]

Years ago I added rear heat to a van. It was a self contained heater core and blower and I just teed into the heater hoses. You'd have to search around but surely someone still makes something like that.

 

[Hoesgottaeat2]

I don’t like that my ‘99 doesn’t have rear heat either. Only A/C in the rear.

 

[east302]

GM would argue that he does have rear heat…it’s just slowly seeping through those little vents on the floor. You could pull the cover off and see if the foam at the floor duct is shot, but it’s probably one of those “as good as it gets moments” if none of the other air dampers are leaking by elsewhere.

And they probably are. The rubber perimeter on them comes apart after a few decades, but you have to pull the dash to get to them.

Picture below shows the foam along with a torn damper, but that’s more critical for a/c since it lets cold air onto the floor when it’s supposed to be closed.

As for swapping a heat and a/c box from a Suburban into a Tahoe, I suppose anything’s possible given parts, time and money.


Tahoe box (evap core only):

Suburban box (evap + heater)

Getting the heater hoses to a donor box from a Suburban is likely a wash compared to aftermarket. The main hiccups would be “would it fit” and how to wire it up.

 

[Joseph Garcia]

Interesting..... I was not aware that some models came with only rear AC and no heat.

 

[Hoesgottaeat2]

Interesting..... I was not aware that some models came with only rear AC and no heat.

Glad we could help you out there