Welcome to AF.
So your cooling fans were turning on at 170 degrees F without A/C operation?
That doesn't sound right. The cooling fans are programmed to turn on at 223 degrees F in low speed and 230 degrees F in high speed. The cooling fans are supposed to turn on with the A/C on as long the refrigerant pressure is greater than 190 psi and that is classified as normal operation not an override mode.
Is the 220 degrees at idle or what condition(s)? It sounds like you have other issues causing the higher than normal engine operating temperature. With engine off unplug the ECT (engine coolant temperature sensor). Then start engine and see if both fans turn on in high speed mode within approximately 5 seconds which is a failsafe mode.
BTW - Mine turn on at 180 degrees in low speed regardless of A/C operation but I have a re-programmed PCM module (Intense).