My model is the basic manual version with a hand wheel for opening the cover. As the cover raises the fan goes on. It has 3 speed settings, but we always leave it on 1. The fan has worked for almost 4 years now, we bought it in Oct 09. We have 2 other FF automatics with rain sensors and they continue to work fine after almost 8 years, and they are run a lot.
The other day when I opened it didn't start. I checked the fuse and it was blown. I put in a new one and when I opened the cover the fan began to turn slowly and then stopped. The fuse was blown again. Did this 3 more times at different speed settings with the same result. I can spin the fan without power and it seems to spin easily. I'm figuring the motor is shorted, so we just ordered a new one from Camping World, they have it on sale now for $94. I think it's worthwhile just swapping it out for new rather than trying to take it all apart. I'm getting a little too old and feeble to be on and off the roof too much.
Thanks for all the comments and suggestions,
Fred