AC in NON AC Comanche

[FarmerBrown5]

Hey guys! I have been considering adding AC to my 92 MJ. My '96 parts XJ had AC. I plan on using the heater box in it to swap out my current heater box in my '92. I know this has been done before, but I cannot find a writeup anywhere for the Comanches. I was hoping someone could point me in the right direction.  

 

Thanks

[ParadiseMJ]

You might want to look at a write up for an XJ, on an XJ forum.  The A/C system is identical and much more common.  Parts AND information.  You can glean the "system" for an r134a compressor and condenser on an XJ in a junkyard but buy NEW hoses, expansion valve, drier/accumulator. 

 

As to the how, I only have a vague idea.

[mikekaz1]

Not sure how much 96 changed its HVAC electronics along with its switch to OBD2. but otherwise it should be a part for part plug and play install. Swap controls and harness, box and cores, compressor and dryers all as a unit. Personally I would buy the cores brand new. But that's just me.

 

If the electronics don't match up or you just feel like doing it alternatively. You could always just hook the compressor up to an ignition on/off switch. The side benefit of this is you can then use AC on all blend settings not just the two designated AC.

[mikekaz1]

I also have a non AC truck. If I ever do the swap I'll probably just do an on/off switch.

[Hippie66]

A.C. running non-stop? I would expect problems there.

[64 Cheyenne]

High and low pressure cut out switches would still need to be in the system, believe they could/would be wired into a simple harness when you powered the system "on".

Pretty sure somebody could make a simple schematic on how it could be wired.

[mikekaz1]

A.C. running non-stop? I would expect problems there.

 

only on when you want it on.

[FarmerBrown5]

Not sure how much 96 changed its HVAC electronics along with its switch to OBD2. but otherwise it should be a part for part plug and play install. Swap controls and harness, box and cores, compressor and dryers all as a unit. Personally I would buy the cores brand new. But that's just me.

 

If the electronics don't match up or you just feel like doing it alternatively. You could always just hook the compressor up to an ignition on/off switch. The side benefit of this is you can then use AC on all blend settings not just the two designated AC.

I was also curious if the '96 wiring would be a problem. I can't imagine it being different, but as you said, its obd2 and could be. If I take the time to do this, I am buying all new components. It won't save me money if I just have to come back and replace it later. 

[Hippie66]

 

 

A.C. running non-stop? I would expect problems there.

only on when you want it on.

Compressor needs to be able to cycle or you will have problems with it freezing up.

[dasbulliwagen]

i swapped AC into my 87 2.5, but I know thw wiring between the 4.0 and 2.5 is much different. The 87 2.5 harness has more similarities to the 86 and earlier jeeps than the newer ones where everything was changed to get the 4.0 to work. My 2.5 had a connector in the engine compartment for dealer added AC which I used combined with factory diagrams in order to make it all work. I don't think the 4.0's had that unless it was all in the harness already and not used. The dash harness had everything there already except for the controls. I also used the HVAC box harness that came with the AC box (Donor was an 86). It all plugged right into dash harness and it all worked on that end.

[Marine1Texas]

Wiring is simple on any auto ac system. a switch that is on your dash turns a relay on, that then supply's the power to engage the clutch on your compressor. As all systems there is a pressure valve on your drier receiver that opens the circuit if enough pressure exists or closes the circuit between the relay and the clutch if pressure is too low. not much to it at all. The relay also turns the electric fan on and off. The only thing extra is on the inside of a vehicle there is a temp switch that will interrupt if the air gets to cold not all have this.

 

Our mjs are the most basic ac systems you can get, you don't even need a harness per say (one wire running from dash to relay under the hood). A relay that connects to a toggle switch on your dash or to your air controls is all you really need (one wire). Most people have the skills to push the button off if it gets to cold. Pulling the power from the ignition so that when the key is off and toggle or which left on, it is off power to the relay. The power coming from the ignition is very low amps, because the harness under the hood is pulling direct from battery source, and low amps from ignition is just to switch on the relay. Just a 30 amp fuse on the power going in to the relay from battery is needed

[ParadiseMJ]

 

  Most people have the skills to push the button off if it gets to cold. 

 

MOST!!  :rotfl2:

 

...others...not so much...

[1989 comanche mj]

I put 96 xj ac on my 92 mj but it had factory ac.  It all swapped over except the high low plugs were different, I cut and swapped the wires.

[FarmerBrown5]

I appreciate all of the input so far! When the shop frees up and we get some things taken care of inside I plan on pulling the 96 back in to pull the box.