I too have gotten away with 12 volts to a 6 volt fan motor. And that is is what I did, got away with it. For the best solution, change to a 12 volt motor if you can find it. If that is not an option, then get a "dropping" resistor, and yes they are big and get hot! You will save the switch and fan control if and only if you have a fuse inline on the main hot wire to the control switch. Oh, the things I used to do. You have spent the time and effort to get the heater and clean it up. You have spent the time to restore it. Don't risk doing it all over because you need a resister. Just my 2 cents worth.
