Need help adding A/C

[bighause]

I am looking for a donor XJ to get the parts I need to add A/C to my MJ. I plan to swap over everything as my truck never had A/C, I'm not sure what years are compatible though. Since I have a renix era truck do all the parts have to also be renix? If the HO era parts would work I would have a lot more options, but I have a feeling I'm not that lucky.

 

Are there any links to this swap? The search won't let you look for "AC" :fs1:

[Eagle]

Ideally you want parts from an 87 to 90 XJ. Jeep stayed with the R12 Freon through '93, I think, but I believe the underhood (and probably under-dash) layout was different for the HO engine vehicles.

 

Conversely, using parts from a 94 - 96 XJ would get you a system that's already set up for and compatible with the RC134 refrigerant. What I'm uncertain about is whether the under-dash controls are compatible ... but I'm sure it could be made to work.

[Gjeep]

I was doing a Renix rebuild on my '89 MJ before I decided to go H.O with it. I bought a NOS Renix era factory r12 retrofit kit for XJ/MJs without factory installed AC. It was near complete with parts and did come with complete instructions. It did not come with the evaporator box specific for AC equipped vehicles...this box/ plastic shell is the same Renix to HO. It also did not have a condenser if I remember correctly (the part located in front of the radiator). The condenser is 99% of the time the same as HO years (unless you have a type 2 style condenser with unique fittings). I can't remember if this kit is a type 2 style or not. If it is type 2, I do have a NOS condenser, if type 1 I do not. Will have to check. Other than those two parts I mentioned it has everything else. New evaporator core, Sanden compressor, brackets, hardware, hoses, labels, etc. Let me know if you're interested. I paid $700 for it back in 2002. I believe I have scanned the installation guide for this kit if you want a copy.

[bighause]

I appreciate the offer but I plan to buy an entire beat up XJ, strip the ac parts, part out what I can and scrap the XJ shell. Hopefully I can recoup most of my cost by doing it this way and have a donor for other misc items I could use.

 

I'm pretty mechanical but this will be my first attempt at any kind of AC work. If the r134 underhood components would work, that would be wonderful

[Sir Sam]

Grab the r134 components from a newer XJ. (94-96) and bolt them in.

[bighause]

What am I in for as far as wiring? Is the wiring there for the compressor, how about the dash controls? I guess no one has a write up for this?

[starkizer]

Maybe when you get it all working you can come to Kansas and do mine? Nah but really tho you should post on the build page and put lots of pictures up and tell us all what it cost to do something like that. I know mine didnt have AC and that is the ONLY thing I don't like about my truck.

[dasbulliwagen]

I did this to mine, but mine is a 4 cylinder and the wiring in the engine compartment is completely different. I swapped the HVAC box, added the compressor and bracketry. Some of the wiring was already there, like the interior wiring for the controls, and the compressor clutch wire, but for the rest of it, there was a connector that was labeled on the factory wiring diagrams as to be used for dealer added AC, so I followed the diagram and made the rest of the needed wiring and relays to properly operate everything. I'm not sure the 4.0 trucks have that same connector or not, as the only one Ive had to look at already had factory AC, but if yours doesnt have AC there might be an unused plug somewhere in there for that purpose. I think mine was a 4 wire plug, with at least a light green wire for the pressure swith, I think an orange wire, and I can't remember what else. Mine was hidden on the driver side over the wheel arch, but I know the factory spot for the 4.0 AC relay is with the relay group on the right side. You might need to do some wiring diagram research to find out exactly how yours needs to be layed out and if there is stuff there already for your setup. Good luck!

[bighause]

From what I can tell by looking under the hood the wiring isn't there. Hopefully I can add the wiring needed like you did, I can't see jeep using different wiring harnesses for the ac option. This is a winter project for me so i'll be sure to take lots of pics when I tackle it. I'd like to drive my truck more but it's too hot in Dfw to not have AC.

[bighause]

Does anyone know if the newer r134 components will work if I am swapping over an entire system?

[dasbulliwagen]

The old R12 parts will work just fine with adapters put on the high and low side charge ports. You just need to make sure you put it on a good long vacuum to get all the old oil out. Mine has been working well like this.

[bighause]

I spent some time this morning at the JY comparing the different era AC components and discovered that they all use similiar wiring connections. The only AC wiring under the hood is for the compressor and the low pressure switch.

 

The hose fittings are going to be era specific, (87-90, 91-93, 94-95) but as long as you grab everything from the same donor any year appears to be a direct fit.

 

My truck does not have the orange and two green wires to connect the compressor and pressure switch, so I'll figure this out how to add these once I find a donor. Hopefully a 94-96XJ