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been there with my 1990 v6 trooper, and I have designed cooling systems for manufacturers so may b able to help.
first off, I doubt your electic fan will move enough air and I would go back to mechanical fan....but first I would get a new one. the OE fans have a hydraulic clutch that may have failed so the fan speed may not have increased with temperature.

overheating on a 50/50 antifreeze takes places at about 250f with stock 16 psi cap but lower temps if caps old and less pressure. change it out. check oil for any moisture to be sure you don't have internal leak and losing pressure (check for moisture on inside of oil fill cap). if you changed your coolant just prior to problem, likely got air in system so burp it.

check radiator shroud for any gaps and seal with RTV or similar....air takes patch of least resistance and could be sucking air around the radiator rather than through.
if you haven't changed thermostat, do it.
I would also check if temp gauge is accurate using a cheap IR thermometer.

another suggestion while troubling shooting is use water instead of's easier and cheaper to drain and replace while trying different will also cool a bit better than antifreeze so reference this when taking temps.
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