Not necessarily
If you have a fan with onboard controller it may only take 0.5ma when its powered up - until it decides to turn on the fan motor windings (some of them have onboard speed controllers) then you're not going to be taking much/any current hence no voltage drop across the resistor.
If the controller sees 9-10 volts instead of the expected 5 then it might refuse to do anything and keep itself turned off (or burn itself out - try applying 10 volts to a Pic Microcontroller
)