[DennisAN]

Be careful to "zero" your meter when dealing with such tiny ohm values. It is possible the measured values in the above post are in error by 0.2 ohms each, when the real values would be 0.0 ohms (i.e. a wire) and 0.6 ohms.

What YEAR is the OP's car? The resistor value appears to vary between model years.

The FSM for 2000+ cars shows only a single resistor per fan motor. Both are shown as 0.55 ohms on the schematic diagram.

To calculate the wattage you have to account for the resistance of both the resistor and the fan motor as they are operating in series to ground. Once you have the overall amperage, you can then backtrack and apply ohm's law to the resistor itself to determine its minimum wattage rating.