viscous fan

Just wondering about my viscous coupling is it dead the fan always spins with the engine running but after a couple of hours drive I can turn the fan with the engine off surely after a couple of hours drive the fan shouldnt move cos the coupling should be essentially seized so it spins at the revs of the engine to maintain cooling? Or am I missunderstanding the way it works

viscous fans don't ever seize solid, (unless the bearing fails) so you will always be able to turn it. It shouldn't ever have no resistance when turning by hand but but it's normally 'just perceptible' resistance, never 'stiff' - i.e. you shouldn't be able to 'flick it' and set it spinning freely, it should stop itself in a second, give or take.

ah ok so I had the right idea just needed the theory taming a bit. ie its always got resistance just a little when cold and more when warm but never locked or full freespin. thanks for clearing that up thats one less thing for me to worry about