I can get it to turn without any force at all but it won't spin freely like some people have suggested, as in, If I spin it it won't carry on spinning, well no more than half a second anyway. Is that how free it should be or is it slightly corroded?

Reason for asking is I had a blocked Pollen filter and drain hole and it's ended up blowing my resistor, no point replacing the resistor if the new 1 is going to blow because the fan doesn't function properly.