KOG nailed it when he described the high pressure fan control switch. When Chrysler re-designed the fan control circuit, they used a pressure switch on the AC high side line to turn on the condenser fans instead the old system that locked the fans on solid whenever the compressor was engaged.
You were undercharged and it appears that when the high side pressure went below about 180 PSI, that pressure switch opened and turned the fans off. I'm not sure what the reasoning was behind this design change, other than to save a miniscule amount of energy by not having the fans kick in for a few seconds while pressure builds. Perhaps it is easier on the electrical system by not having all the stuff coming on at the same time.
If your cooling is sufficient, don't do anything. If you want to chance adding more refrigerant, get gauges on it so you don't overcharge it.
Anyhow, it was a long discussion getting to this point, but I think a few of us learned a little bit more about the 94 fan design circuit. I hope the new refrigerant stays in there for a long time.