Two basic rules of troubleshooting. Pick one:
1 - Start with the most likely problem first, because you'll spend less time if the most likely problem IS the problem.
2 - Start with the easiest-to-check things first, and work up to the more difficult things, because why go to more effort than you have to?
Those two rules sometimes go together, sometimes not. In this case, they probably do. Start with the fuse (if the fan is 12vDC) or the circuit breaker (if the fan is 120vAC). Not only the most likely place to start, but also the easiest.
I thought getting old would take longer!