adding AC to a non AC truck

[ICEBOX]

Ok I bet it's in here some place but i can't find it. has anyone added on AC to a non AC truck . if so how esy or bad was it . any tips :) thanks guys

[Druville]

ive been thinking about this as well. i have an ac equipped parts truck and my comanche is a hot box of sweat. i was just thinking about pulling every ac component off the parts jeep and laying it out then piecing it back together from there. ac confuses the hell out of me ive only had one vehicle were i even used it but man its nice when I'm feeling like a baby or having a female in the truck.

[835]

Depending on what you want to call easy or bad; I have done two trucks already that did not have A/C in them.

Do you have already the xj/mj to get the parts from?

you have to pull the dash out, plus remove some of the wire harness from the compressor to the a/c panel, also going to need the a/c- heater control panel. remove the bolts/nuts from the engine bay to get the a/c- heater box out.

you have to swap out the whole heater box you have now, since it does not have a spot for the a/c evaporator. to go into.

I don't mess around with used a/c parts, since you don't know how long they will last. I buy all new and know what I have, that and the cost of R22 any more you don't want to be putting used parts in; then three months later replacing them.

This is what I buy new;

a/c lines [ high side & low ]

Dryer

expansion valve

compressor

condenser

evaportor

Total on the above new, around $400. [ I get a small discount at Napa ]

I will be doing this soon to the truck I have now, since it don't have a A/C and I live in Florida with a 110 heat index.

It's best you have the xj/mj at your place so you can take the time to pull the parts off and you can see how the wiring goes.

You can pull/ take one wire out at a time and install in your truck. It makes it a lot easyier. the parts are pretty straight forward, if need to take a picture of what it looks like with what a/c line goes where.

When I do mine, I will take pictures to put on the DIY, but this might not be for another couple of months, I already have the parts for it just need a few things at napa, that and the time to pull the dash out.

[ICEBOX]

I work for NAPA so I'm good there. And thank you for the great info . I do have a XJ with ac in it now.

I'm thinking I want to put the ac in my MJ . I drive it every day .

[Druville]

yea thanks for the info and def good call on replaceing wearable parts. i work at a lesser autoparts store but hopefully that will help get the price down a bit.

[thejim42]

are the parts the same on all year mj/xj's?

[92tanMJ]

are the parts the same on all year mj/xj's?

86-91, 92-96, 97-01 but I would assume 86-96 would be the same

[thejim42]

well the dash was the same so i assume the climate box and controls would be, i just wasnt sure about lines, compressor or condenser...probably parts i don't want to get used anyway

[01yellowxj]

What about putting AC in a 4 cyl MJ? My wrecked XJ out back has all the parts and is still a sealed system as I have not craked anything open but it was a 4.0 XJ, compressor mounted up by the battery/rad area. Not sure where the AC compressor goes on a 4 cyl motor.

[gconcilio]

Does NAPA have an evaporator that fits into the Comanche?  What is the part number?  Everything that I can find is too big.

[lil_loco]

Gonna revive this.... trying to install AC into my 2.5l i4 86. I pulled the plenum box and interior wiring/lines from a 1990 XJ with 4.0l unfortunately there are no 4cyls left around here in the same generation. As far as wiring goes does anyone have references or able to recall from experience what goes where? 

 

Ive done AC in a TJ before using a donor for the parts I couldn't get new. But this is a totally different animal - my TJ was prewired for simplicity at the factory so slapping on a compressor, changing a belt and popping in a relay was all it needed as far as powering the system went. 

 

Ive yet to see if the MJ was a lucky recepient of lazy with a prewired harness. But I'm skeptical. 

 

Please chime in :)

[BryceOJ]

I'm an interested in doing this to my mj as well.  And how it will be done on a 2.5l.   I know that if I find a jeep 2.5 of the same era I'm jumping all over it but havent seen one yet.  I assume installing a/c on a 2.5 may have slight variations compared to the 4.0 i donno for sure though

[lil_loco]

Yea that's the issue. So many folks claim a.c. on their rigs but no write ups yet found

[Zebvance]

I would install ac into my 88 Mj but I don't want to deal with having to take the dash off...

[lil_loco]

I would install ac into my 88 Mj but I don't want to deal with having to take the dash off...

That's the easy and fun part in my books! The wiring scares me.

 

took about 1.5h in a farm field with a break half way through to hide from the p'd off snakes that had made a nest in the plenum box. The dash doesn't have to come apart just unhinged at the bottom after you clear the clutter (console) two bolts easy peasy.

[sloride]

As for finding a replacement evaporator question fitting in an MJ, good luck finding one that fits.  The later models might have a replacement, but finding one that fits for my '88 hasn't proven successful.  I tried 4x4Morris because they said they had one.  Placed an order and it was a 60-90 day wait.  Okay, no problem.  I can wait provided it will work.  After 90 days I called and they contacted their vendor about ETA.  Vendor decided they're not making that anymore.  I've tried several evaporators of different configurations, but still not luck.  There's the serpentine style where the coils snake vertically up then down type construction, which will fit but then you have the capillary tube location you have to deal with.  The tube can't go into the back of a serpentine style like on the stock unit, so you have to place it through the top or side of evaporator.  Then theres the one of horizontal coil construction with the spaghetti of coils to the two fittings that come out one end.  That one will fix your capillary tube placement issue but the spaghetti of coils coming out the one end make it not fit the box.........  I finally decided to flush my evaporator core and put it back in the heater box.  Took it to Aamco (transmission place) and they flushed it clean.  I hope to reinstall my heater box this week end.....  On a side note.  I did get new lines from JeepAir in Florida.  My photobucket has pics of the lines with the part numbers I used.

[Comanchemodder]

As for finding a replacement evaporator question fitting in an MJ, good luck finding one that fits.

Most likely it will be easer to change the heater box from an XJ with factory air.  Thats what I did.  Now any XJ evaporator core fits like a glove.  The factory air heater box is bigger than a non-ac heater box (it was in my 87 comanche anywhy)

 

Standard evaporator core compared to dealer installed AC and Heaterbox.  As you know its too big:

 

 

 

XJ Heater box with factory AC has buldge to fit the bigger core:

 

[lil_loco]

Glad I opted to strip an xj with factory air. That's the same style plenum box I pulled

 

:)

 

But what about wiring? Any scrap notes or manual pages to reference? I'm not trusting Haynes or Chilton on this

[Peterjojo]

This is an old thread. Does anyone have any updates on this?  I looked into buying a kit from ready made air in Texas but it’s like 1200$. I have an 87 Comanche that I love but the lack of AC is killing me. 

[DesertRat1991]

I've been looking into this recently myself.  I think I have the hardware mostly figured out, but the electrical part has me confused.   Biggest questions:

 

1) Does anyone know if the 91+ trucks are pre-wired for A/C?

 

2) Where is the "cabin thermostat" (temperature sensor) located?  Or, what tells the compressor to cycle on/off?  

[dvitha]

On the few trucks we installed ac from non factory the wiring was not their that was on 86/87/88. We used a factory ac box and factory ac dash unit. we wired the button to a relay that kicked on the compressor and the fan same time. We did not install a cabin thermostat. We did this for the 3 trucks at the shop about 15 years ago.

[Minuit]

On 8/6/2018 at 10:20 AM, DesertRat1991 said:

2) Where is the "cabin thermostat" (temperature sensor) located?  Or, what tells the compressor to cycle on/off?  

 

There is a thermocouple probe in the A/C evaporator that will turn the compressor off if the evaporator reaches a certain temperature to prevent it from freezing up. Aftermarket evaporators usually eliminate this. This is critical to the function of the system, as the only other cycling control is a hi-lo cutoff switch located in the receiver/drier. This will only disable the compressor if there is no refrigerant in the system or there is a dangerously high pressure in the system. Without the probe, the compressor is essentially uncontrolled. This is not the intended behavior of the system and can lead to evaporator freezing or worse.

 

(you guys should probably start a new thread)

[Comanche chief]

I am about to attempt this with a 1993 Jeep Cherokee, as a donor vehicle, on my 1988 Jeep Comanche 4.0 non factory ac truck. I'm sure if all else fails I'll be able to get the AC to work with an aftermarket switch and relay set up for the compressor and fan. I'm wondering if there's other components in the wiring that communicate with the Renix computer to idle up and down with the compressor cycle? 

[Peterjojo]

Comanche chief. I love that you’re doing this as I’m about to do the same thing and I like that you’re doing it in 2019. As opposed to 2011. When this thread began. 

Where have you sourced your parts?

[m2bandit]

On 5/16/2019 at 6:19 PM, Comanche chief said:

I am about to attempt this with a 1993 Jeep Cherokee, as a donor vehicle, on my 1988 Jeep Comanche 4.0 non factory ac truck. I'm sure if all else fails I'll be able to get the AC to work with an aftermarket switch and relay set up for the compressor and fan. I'm wondering if there's other components in the wiring that communicate with the Renix computer to idle up and down with the compressor cycle? 

I just pulled everything from a donor and compared my harness. There is absolutely no AC related wiring in my 88 Chief. 

In the donor there's a green and black wire. It goes to a few places  starting at the AC control switch but ends up at the ECU. Most likely for the idle up.