The way I tested my fan was by running two wires from the battery and to the fan - positive on one side and negative on the other. (I stuck the wires into the plug. Make sure you have a good connection to the wires.) By doing this, your fan should turn on.
I think it is a good idea There is nothing worse than being stuck in the middle of nowhere because of a sensor..... You just have to make sure you turn it off before water crossings and make sure to turn it on....
