I imagine, if i replace the fuse, and i turn on the fan again and it blows right away, what would be the next step to check? Does that mean the resistor pack needs replacement? Is there any way to test the motor itself?
Typically the RP fails open, so that would mean no fuses should pop. I had the same thing as you happen with some heavy rain, but, instead of popping a fuse as God intended, my fan speed knob caught on fire... Remove the water though and the problem goes away.
"Lots Of Trouble; Usually Serious"