Universal AC Conversion?

[RustCollector]

I have an '88 Suburban. Apparently the original owner, who purchased it in Scottsdale ARIZONA, didn't see any value in rear air. When I first bought the truck as a bachelor it only bothered me a little. Now I have a family and the real possibility of using this beast to transport them in all it's 9mpg glory.

The front air that's in it is questionable at best with all the flaps sticking, the vents busted, the ducts crumbling, and the controls require a hammer to move. Heat quit working years ago. I took a stab at fixing it once upon a time, but the under dash stuff and firewall bits ain't designed for easy service.

I am considering doing some custom dash work... like a whole new custom cap and cluster. I'm also considering, as part of that effort, installing a universal evap (like $100 on ebay and amazon), one up front, one in the back. Just start fresh with the whole dang system. Doubt I could fix what's in there for less, and budget matters here.

I'm thinking of grabbing a factory compressor and splitting hoses (y-pipes?) meant for a dual AC truck (rock auto or autozone), then everything past those lines would be custom/universal, including a universal heater core system.

Thoughts? Suggestions how to pull it off? Other recommendations to make climate control work and liveable?

I'm in the planning phase still, so I'm open to other ways, but given the scope I just want to plan it right... I'm a current ME and former HVAC tech, so custom doesn't scare me, but a rabbit hole of domino part failures in the factory system does. I ain't got the time or money for those games

 

[gmbellew]

it is probably easiest to fix what you have and get stock replacements to add the rear air in. I agree, that the suburban really needs the rear air for passengers. you can live without heat back there. I frequently have 3 kids in my 90 burb and I just keep some small blankets to help when it is really cold.

you can see the main hvac door operations by dropping the glove box and the vertical duct piece. if the heat doesn't work and you don't have a coolant leak, there is probably some relatively easy things thst could be the issue.

 

[gmbellew]

https://www.gmsquarebody.com/threads/heat-ac-blend-doors.30548/

a good thread and there are others if you search

 

[RustCollector]

Last time I priced it through LMC I was looking at over $2k to replace what's bad and add the factory rear air system, and even with that I'd be begging, borrowing, and stealing from junk yards hoping to find the last few pieces for the conversion... which I would need a sample truck in front of me to even know what those last pieces were. I guess that investigation just turned that switch off and built a wall around it for me. If I'm gonna dump that much in, I figured I'd just go buy another Suburban with it already there, which is just as unrealistic.

Is there a better way to source the "conversion" that I'm just missing? These trucks have turned into hens' teeth in the junk yards.

 

[gmbellew]

you may try to see what you can source from ebay...I have scored good parts, but it can be hit or miss.

 

[Goldie Driver]

I wonder if the next body style up ( 92 up ) would let you get hoses, y pipes, etc.

That body style does not have the forward facing vents, but, maybe doing it custom would save money.

I got lucky on the 91 I added rear air to and found what I needed in the junkyards.

I had an auto ac place install it and charge it- what I had not thought about was the cost of R12, and that was in 2001 or so.

You might change to 134 at the same time .

Or, maybe look at this :
https://www.ebay.com/p/920998357

No idea on that - was just doing a quick search for some propane replacement for R12.

Could not find that info, but found the above.

 

[RustCollector]

You might change to 134 at the same time .

It's already converted to 134.

If I remember right the GMT 400 had it roof mounted behind the front seat with another box under the seat. Been a while since I wrenched on one though. A custom headliner would be a heck of a project, but I guess it's worth investigating, especially since my "guaranteed not to sag" LMC liner didn't survive its first AZ summer.

Anyone well acquainted with the 92-99 with rear air... your expertise of the system components or what might be involved in such a retrofit would be welcome

 

[RustCollector]

Scratch that. My memory was close but foggy. Looks like it was incorporated into the headliner. The thought of trying to make a GMT400 headliner fit in a GMT100 chassis makes the universal units look like childs play...

 

[Craig 85]

I purchased a lot of new OEM parts to fix my system and went with a Sanden compressor. By the time I bought all the parts, brackets, etc. it was about the same cost as a Vintage Air system. For the rear, I've seen street rods run A/C in the trunk. Classic Auto has the system below to give you an idea.

https://www.classicautoair.com/shop/complete-ac-systems/trunk-mounted-air-conditioning-system/

You must be registered for see images attach

 

[RustCollector]

I purchased a lot of new OEM parts to fix my system and went with a Sanden compressor. By the time I bought all the parts, brackets, etc. it was about the same cost as a Vintage Air system.

Right that's like what I'm talking about. I mean admittedly I'm talking the cheap chinese knock offs of vintage air, but same general concept.

Just fixing my underdash evap box is a ton of money and effort. The plastic is all old, brittle, and past its expiration. By the time i fix/buy/fab everything, particularly adding rear air, I'm 80 or 100 hours in and $2k+ invested. For less time and money I could do the fab work necessary to fit two brand new evap units with fresh plastics, controls, metal, and I won't have to worry about all the shoddy engineering of late 80's GM trying to save a buck while maintaining "marketable" complexity.

It would also give me all new wiring and ducting so I'm not chasing failures trying to tap into 33 year old junk no one would take at a junkyard if it was free.

Only hang up is the aftermarket systems weren't intended for dual air, which is what I have to figure out how to execute. I just don't know the rear air systems well enough to know what all I need to put between the condenser and evap.

 

[1979k10]

I’d just call up both Vintage Air and old Air and speak with tech. See what options they can set you up with the builder series of products.

 

[Keith Patton]

you can also try OLD Air Products in Ft Worth, that's where I parts and Sanden compressor..