Rear Air Conditioning

Finally got rear AC working on my wagon.  Installed the rear HVAC unit out of a 2012-ish Suburban in the driver's side rear storage compartment.  Had to cut off the heater portion of it to make room and I still need to make the actual vent and wire in fan speed controller (currently just on or off).

Ran about 20-25' of liquid and suction lines along the frame and over the rear axle to the back.  Teed the suction line between the front evaporator and the accumulator and the liquid line right at the condenser outlet.  Also had to relocate the front orifice tube.  Had to lower the drivers side muffler with longer hangers to leave clearance for the plumbing to attach underneath.

Probably spent $400-$500 including the AC line crimping tool.  I had to replace the compressor anyway (not included in that price) so decided this was the time to do it.  It ended up taking about 4 lbs of refrigerant to get up to the correct pressures.

https://imgur.com/a/j6XaiJI

That has a few pictures. I can add some more of how other things were done. Hardest parts were planning it out and getting the orifice tube relocate kit to properly seal.

Interesting project!

Looks like ac unit fit decently well in that cubby space. I bet the car will cool inside better now!

When my wife had her '89 Suburban it only had the regular ac and it was converted to 134a. It struggled to keep the interior cool, front seat area was ok but the rest of the truck would be barely cool.

Do vehicles that have front and rear ac have larger compressors or larger condensers?

I had to do a fair bit of trimming to the unit to get it to fit, like I said I had to cut off the whole heater core.

The middle seats seem fine with just the fronts going, but the rear was way to hot, especially since I have my dogs back there a lot. This should help that a lot.

And it seems like on a lot of cars they will use a different compressor and condenser with rear AC. Sadly I don't think there's a great upgrade (besides the high efficiency compressor I installed) for these cars, but I might swap to dual electric high CFM fans and adjust how they turn on when the AC is running.

Great idea and nice job. When I put l kids in the rear facing seat they love the ride but sweat their heads off. I suppose this is only for those in warm climates since there is now no heater.

I probably could've made it fit with the heater if I had used the spare tire compartment instead of the rear storage (it also would've been easier to run the AC lines since I wouldn't have needed to go across the car), but I wanted to keep the spare tire and it usually doesn't get cold enough in Texas to justify rear heat. I figure I can give backseat passengers a blanket if they need it.

any updated info on how the vents and controls are completed?

I wish. Had a daughter back in April so haven't gotten a lot of time to work on it.

Congratulations on the birth of your daughter. I have 3 and they love riding in my wagon although I’m sure they’d enjoy it more if I could keep the back of it cooler in the summer! Looking forward to more updates