Need AC Donor System and/or Parts List Schematics for 74 J Series

[briggss3]

Anyone know of a donor vehicle around Houston? Also, I wonder if its possible to build a factory AC system for my 74 J20 (401) through parts stores like Autozone.

Also if anyone has a parts list and schematic for a complete AC system, that would help. I find things like compressors and expansion valves easily, but I really don't know what all I need for the whole system.

I have basic mechanic skills but have never done AC before. I would like to get a system and vacuum test it before I install it. Once in, I can take it to my AC shop.

Been hitting salvage yards and ebay already with not much luck.

[babywag]

oljeep.com has manuals

I'd seriously consider an aftermarket vs. stock system.
Get waaay better system and can also ditch monstrous heater box under the hood.

[joe]

I'd seriously consider an aftermarket vs. stock system.
Get waaay better system and can also ditch monstrous heater box under the hood.

+1

[briggss3]

Any one in particular? I was looking at the Vintage Air system, but honestly I have no idea what's involved to put one in a J Truck. Called one of their suppliers and they quoted me $3000 installed, so that takes them out of the mix. Called Vintage air, but they said it would have to be a custom made to fit job for Jeep trucks or wagons.

BJs has a kit, but the short searching i did gave me no feel on whether its worth the price or any good.

Forum searches seem to bring up the idea that its best to find an OEM system off a parts vehicle.

If anyone has a detailed vintage air install thread, let me know. I found one good thread, but it was a body off build thread that the A/C was added in as a part of the build.

[tgreese]

The under-dash unit, including evaporator and fan, is separate from the heater. You can take these parts from a wreck and use new parts under the hood. The aftermarket AC companies will help with this, AFAIK. These parts will be shown in the parts manual at oljeep.com, though the transfer of that manual is not great. Maybe find a friend with a printed copy of the '74-80 parts manual.

Back in the day, there were universal AC units that bolted under the center of the dash. Kinda think the in-cabin unit for a pickup cabin especially is not particularly difficult to work out. Lots of air conditioning kits at Summit Racing: https://www.summitracing.com/search?...20conditioning

You could probably make this work https://nostalgicac.com/complete-ac-...0-engines.html - and since this company offers brackets for the AMC V8, possible they will sell you parts to piece together a new system for a J-truck.

One of these aftermarket air conditioner companies had a primer on their site about putting together an AC system from individual pieces ... some search would likely find it again. Going to require some study and research by you.

Check also on fsjnetwork.com - pretty sure this has been covered there. Hard to believe there are no old posts here that cover AC installation.

https://www.google.com/search?source=hp&ei=eBDfXMWnBez45gKl9rSYCA&q=site%3Aifsja.org+air+conditioning+installation&oq=site%3Aifsja.org+air+conditioning+installation

[briggss3]

Thanks. I found a thread by sonoraed on Full Size Jeeps. Sounds like he sells Vintage Air and quite a few folks are happy with the Magnum IV from them. I sent him a PM to see what he says. Will update this thread.

[babywag]

I rebuilt the whole system in my 88 after buying it.
By the time I was done a brand new aftermarket system could have been had.
To this day I regret that decision lol.

[Towtruck]

As tgreese pointed out, the stock heater and AC systems are independent. So the big heater box under the hood stays unless an aftermarket AC kit has a built-in heater core...doubtful. The factory under dash AC unit in my J10 will freeze me out of the cab in August heat (DFW area).

[Mikel]

As tgreese pointed out, the stock heater and AC systems are independent. So the big heater box under the hood stays unless an aftermarket AC kit has a built-in heater core...doubtful. The factory under dash AC unit in my J10 will freeze me out of the cab in August heat (DFW area).

I have a 1960s Super Wagoneer -type A/C in my J300, running R134A with a modern condenser and sanden compressor. It works surprisingly well and it is cool as hell (pun intended)


I do miss the flexibility of a modern HVAC system (A/C defrost, being able to blow hot air out of the dash vents), but we all have our preferences.