This summer I plan to get A/C working again on my engine swap. My Jeep being an 85' it uses the older tube style evap core with the hole for a needle shaped probe for the temperature switch, but newer Cherokees (I can't seem to find the cutoff year) don't have this hole for the probe but I also can't find anything about how they monitor the temperature of the evap core. If somebody knows how the system works on newer XJs and maybe even has a part number and wiring diagram it would be greatly appreciated!

 

You can use the same thermistor you just need to drill a hole in the HVAC box so the probe goes in front of the evap. I just attached it to the face of the evap using mini zip ties through the fins. It has been blowing fine with no ill effects. I fully upgraded my AC in the 88 to 95 parts all converted well. It takes a little care to make the new evap fit the box, but even that wasn't too bad.

 

Later XJs used a pressure cycling switch on the low side line instead of a temperature probe on the evap core. The switch, screwed into the accumulator or line, cycles the compressor based on low-side pressure, which correlates to temperature. You can find the switch and diagram for a '91-96 Cherokee. Just match your refrigerant type.