I installed a bypass switch on my ATV electric fan for the mud pit. I agree about not needing the fan driving down the road, but it still adds a certain amount of risk. If I remember right, on my ATV, my three position toggle switch cuts the thermo switch in the middle position and operates directly from the battery on low position. High position operates through the thermo as normal. It uses relays, but it's been wired since '08 and I'd have to look for the constructions on how it wired.