When in doubt, consult your FSM. The answer is on page 7-9.
In a nutshell it says that with or without the AC on, the electric cooling fan turns on when the coolant temp is at least 223* F and remains on until the temp drops to 217* F or below.
What is confusing is the next sentence which states it will come on if the AC system pressures reach 300 +/- 20 psi and continue to run until pressure drops to 235 psi.
They make it sound like these conditions are independent of one another but I'm betting that if your AC pressures are that high that the fan would turn on, the engine temps would likely already be in the range for it to turn on as well. And as a caveat, I know nothing about the AC system...
2000 XJ "PROJECT RUBICON" 3-link front / 4-link rear / coilovers / running 37's on Dana 60s
My website - EricsXJ.com