It is same with A/C on or off. Before I start the car for the day the fan has a good bit of resistance when you try to spin it. After it runs hot and I turn engine off, if I try to spin it, it is a little stiffer but you can still turn it no problem. It doesn't spin easily but it is not fully engaging. I read online that some Viscous Clutch Fans should not be able to turn after engine runs hot and is turned off as they should turn with the engine until cooled down to a certain temperature.

Also...just thought of something. I had my engine replaced. I noticed that the bearing bracket sits closer to the engine than my older engine and bearing bracket (pulleys still line up fine) but could it be that I have the wrong style fan or clutch for the replacement engine?