I would see this atm when i'm 3 sheets to the wind. Just keep in mine I'm about a liter of vodka and a little over a bottle of champagne in so gauge accordingly.
Now for attempt number two at typing this.... That resistor should be safe up to 7v depending on how you wire it. As with anything, check it for heat before leaving it unattended after some test time and you should be fine. I presume your comfortable with a little testing as you can buy a complete unit for $40 or less with a warranty.
also, be careful if you go the VD route as I just either fried a fan from that or (more likely) lack of magnet balance.