It could be relays. Again, use a voltmeter to see if the fan gets current when the cycle starts. If not, then it could be a relay stuck, if the relay isn't stuck, then its going to be a little more complicated.
I had a fan motor go bad on me a few weeks ago, and I did the same thing you did: checked everything, couldn't figure it out, etc... Then I hooked it up to my $10 voltmeter from Radioshack, and I discovered that the motor was getting a current, so the motor was the problem.
You just have to figure out where the 12v current starts, and where it ends (FYI, it should end at the motor )