I guess you've got a different configuration than ours. And my post missed your point.

That said, I did check the hoses again. We do have a second air hose without a fan that leads from the floor behind the engine to the grate on the stern. So, when the fan is off and boat is cruising, air must enter at the base of the windshield, go below the floor amidship, move rearward through the bilge, and then discharge in three places: at the two little discharge grates on the back of the engine cover and at the second air hose that leads to the plastic grate at the stern.

So, after all that, I haven't given you a bit of help on removing the fan. Good luck, viper. ( By the way, mine is also starting to make some sort of screaming noise also.)